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Full vulnerability report · 2026
CVE-2026-64065High confidence

netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call

Linux · Linux

5.5MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 89 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Low, lowered one band.downgradedsince 19 Jul 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.16% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Linux Linux and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 89 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

17 package states
Package result overrides the generic status

BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 13 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.

Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.6.12.94-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcelinuxNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.7.0.12-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.7.0.12-1Debian Security Tracker ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-aws-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-fde-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-nvidia-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gcp-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-lowlatency-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-nvidia-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oem-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oracle-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-riscvAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical Ubuntu Security ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-64065 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykernel: netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call
76 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • kernel as a component of Red Hat Enterprise Linux 10
  • kernel-64k as a component of Red Hat Enterprise Linux 10
  • kernel-64k-core as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug-core as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug-devel as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug-devel-matched as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug-modules as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug-modules-core as a component of Red Hat Enterprise Linux 10
  • kernel-64k-debug-modules-extra as a component of Red Hat Enterprise Linux 10
  • kernel-64k-devel as a component of Red Hat Enterprise Linux 10
  • kernel-64k-devel-matched as a component of Red Hat Enterprise Linux 10
Summary
A flaw was found in the Linux kernel's network file system (netfs) component. This vulnerability, located in the netfs_write_begin() function, can be triggered by a local user through specific file system operations. Successful exploitation leads to a kernel bug and system crash, resulting in a denial of service (DoS) for the affected system.
Remediation
Fix deferred
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-45638

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 89 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call The multiple runs of generic/013 test-case is capable to reproduce a kernel BUG at mm/filemap.c:1504 with probability of 30%. while true; do sudo ./check generic/013 done [ 9849.452376] page: refcount:3 mapcount:0 mapping:00000000e58ff252 index:0x10781 pfn:0x1c322 [ 9849.452412] memcg:ffff8881a1915800 [ 9849.452417] aops:ceph_aops ino:1000058db9e dentry name(?):"f9XXXXXX" [ 9849.452432] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 9849.452441] raw: 0017ffffc0000000 0000000000000000 dead000000000122 ffff88816110d248 [ 9849.452445] raw: 0000000000010781 0000000000000000 00000003ffffffff ffff8881a1915800 [ 9849.452447] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) [ 9849.452474] ------------[ cut here ]------------ [ 9849.452476] kernel BUG at mm/filemap.c:1504! [ 9849.478635] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 9849.481772] CPU: 2 UID: 0 PID: 84223 Comm: fsstress Not tainted 7.0.0-rc1+ #18 PREEMPT(full) [ 9849.482881] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-9.fc43 06/1 0/2025 [ 9849.484539] RIP: 0010:folio_unlock+0x85/0xa0 [ 9849.485076] Code: 89 df 31 f6 e8 1c f3 ff ff 48 8b 5d f8 c9 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 48 c7 c6 80 6c d9 a7 48 89 df e8 4b b3 10 00 <0f> 0b 48 89 df e8 21 e6 2c 00 eb 9d 0f 1f 40 00 66 66 2e 0f 1f 84 [ 9849.493818] RSP: 0018:ffff8881bb8076b0 EFLAGS: 00010246 [ 9849.495740] RAX: 0000000000000000 RBX: ffffea00070c8980 RCX: 0000000000000000 [ 9849.498678] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 9849.500559] RBP: ffff8881bb8076b8 R08: 0000000000000000 R09: 0000000000000000 [ 9849.501097] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000010782000 [ 9849.502108] R13: ffff8881935de738 R14: ffff88816110d010 R15: 0000000000001000 [ 9849.502516] FS: 00007e36cbe94740(0000) GS:ffff88824a899000(0000) knlGS:0000000000000000 [ 9849.502996] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9849.503810] CR2: 000000c0002b0000 CR3: 000000011bbf6004 CR4: 0000000000772ef0 [ 9849.504459] PKRU: 55555554 [ 9849.504626] Call Trace: [ 9849.505242] <TASK> [ 9849.505379] netfs_write_begin+0x7c8/0x10a0 [ 9849.505877] ? __kasan_check_read+0x11/0x20 [ 9849.506384] ? __pfx_netfs_write_begin+0x10/0x10 [ 9849.507178] ceph_write_begin+0x8c/0x1c0 [ 9849.507934] generic_perform_write+0x391/0x8f0 [ 9849.508503] ? __pfx_generic_perform_write+0x10/0x10 [ 9849.509062] ? file_update_time_flags+0x19a/0x4b0 [ 9849.509581] ? ceph_get_caps+0x63/0xf0 [ 9849.510259] ? ceph_get_caps+0x63/0xf0 [ 9849.510530] ceph_write_iter+0xe79/0x1ae0 [ 9849.511282] ? __pfx_ceph_write_iter+0x10/0x10 [ 9849.511839] ? lock_acquire+0x1ad/0x310 [ 9849.512334] ? ksys_write+0xf9/0x230 [ 9849.512582] ? lock_is_held_type+0xaa/0x140 [ 9849.513128] vfs_write+0x512/0x1110 [ 9849.513634] ? __fget_files+0x33/0x350 [ 9849.513893] ? __pfx_vfs_write+0x10/0x10 [ 9849.514143] ? mutex_lock_nested+0x1b/0x30 [ 9849.514394] ksys_write+0xf9/0x230 [ 9849.514621] ? __pfx_ksys_write+0x10/0x10 [ 9849.514887] ? do_syscall_64+0x25e/0x1520 [ 9849.515122] ? __kasan_check_read+0x11/0x20 [ 9849.515366] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.515655] __x64_sys_write+0x72/0xd0 [ 9849.515885] ? trace_hardirqs_on+0x24/0x1c0 [ 9849.516130] x64_sys_call+0x22f/0x2390 [ 9849.516341] do_syscall_64+0x12b/0x1520 [ 9849.516545] ? do_syscall_64+0x27c/0x1520 [ 9849.516783] ? do_syscall_64+0x27c/0x1520 [ 9849.517003] ? lock_release+0x318/0x480 [ 9849.517220] ? __x64_sys_io_getevents+0x143/0x2d0 [ 9849.517479] ? percpu_ref_put_many.constprop.0+0x8f/0x210 [ 9849.517779] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 9849.518073] ? do_syscall_64+0x25e/0x1520 [ 9849.518291] ? __kasan_check_read+0x11/0x20 [ 9849.518519] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.518799] ? do_syscall_64+0x27c/0x1520 [ 9 ---truncated---

What

In the Linux kernel, the following vulnerability has been resolved: netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call The multiple runs of generic/013 test-case is capable to reproduce a kernel BUG at mm/filemap.c:1504 with probability of 30%. while true; do sudo ./check generic/013 done [ 9849.452376] page: refcount:3 mapcount:0 mapping:00000000e58ff252 index:0x10781 pfn:0x1c322 [ 9849.452412] memcg:ffff8881a1915800 [ 9849.452417] aops:ceph_aops ino:1000058db9e dentry name(?):"f9XXXXXX" [ 9849.452432] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 9849.452441] raw: 0017ffffc0000000 0000000000000000 dead000000000122 ffff88816110d248 [ 9849.452445] raw: 0000000000010781 0000000000000000 00000003ffffffff ffff8881a1915800 [ 9849.452447] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) [ 9849.452474] ------------[ cut here ]------------ [ 9849.452476] kernel BUG at mm/filemap.c:1504! [ 9849.478635] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 9849.481772] CPU: 2 UID: 0 PID: 84223 Comm: fsstress Not tainted 7.0.0-rc1+ #18 PREEMPT(full) [ 9849.482881] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-9.fc43 06/1 0/2025 [ 9849.484539] RIP: 0010:folio_unlock+0x85/0xa0 [ 9849.485076] Code: 89 df 31 f6 e8 1c f3 ff ff 48 8b 5d f8 c9 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 48 c7 c6 80 6c d9 a7 48 89 df e8 4b b3 10 00 <0f> 0b 48 89 df e8 21 e6 2c 00 eb 9d 0f 1f 40 00 66 66 2e 0f 1f 84 [ 9849.493818] RSP: 0018:ffff8881bb8076b0 EFLAGS: 00010246 [ 9849.495740] RAX: 0000000000000000 RBX: ffffea00070c8980 RCX: 0000000000000000 [ 9849.498678] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 9849.500559] RBP: ffff8881bb8076b8 R08: 0000000000000000 R09: 0000000000000000 [ 9849.501097] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000010782000 [ 9849.502108] R13: ffff8881935de738 R14: ffff88816110d010 R15: 0000000000001000 [ 9849.502516] FS: 00007e36cbe94740(0000) GS:ffff88824a899000(0000) knlGS:0000000000000000 [ 9849.502996] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9849.503810] CR2: 000000c0002b0000 CR3: 000000011bbf6004 CR4: 0000000000772ef0 [ 9849.504459] PKRU: 55555554 [ 9849.504626] Call Trace: [ 9849.505242] <TASK> [ 9849.505379] netfs_write_begin+0x7c8/0x10a0 [ 9849.505877] ? __kasan_check_read+0x11/0x20 [ 9849.506384] ? __pfx_netfs_write_begin+0x10/0x10 [ 9849.507178] ceph_write_begin+0x8c/0x1c0 [ 9849.507934] generic_perform_write+0x391/0x8f0 [ 9849.508503] ? __pfx_generic_perform_write+0x10/0x10 [ 9849.509062] ? file_update_time_flags+0x19a/0x4b0 [ 9849.509581] ? ceph_get_caps+0x63/0xf0 [ 9849.510259] ? ceph_get_caps+0x63/0xf0 [ 9849.510530] ceph_write_iter+0xe79/0x1ae0 [ 9849.511282] ? __pfx_ceph_write_iter+0x10/0x10 [ 9849.511839] ? lock_acquire+0x1ad/0x310 [ 9849.512334] ? ksys_write+0xf9/0x230 [ 9849.512582] ? lock_is_held_type+0xaa/0x140 [ 9849.513128] vfs_write+0x512/0x1110 [ 9849.513634] ? __fget_files+0x33/0x350 [ 9849.513893] ? __pfx_vfs_write+0x10/0x10 [ 9849.514143] ? mutex_lock_nested+0x1b/0x30 [ 9849.514394] ksys_write+0xf9/0x230 [ 9849.514621] ? __pfx_ksys_write+0x10/0x10 [ 9849.514887] ? do_syscall_64+0x25e/0x1520 [ 9849.515122] ? __kasan_check_read+0x11/0x20 [ 9849.515366] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.515655] __x64_sys_write+0x72/0xd0 [ 9849.515885] ? trace_hardirqs_on+0x24/0x1c0 [ 9849.516130] x64_sys_call+0x22f/0x2390 [ 9849.516341] do_syscall_64+0x12b/0x1520 [ 9849.516545] ? do_syscall_64+0x27c/0x1520 [ 9849.516783] ? do_syscall_64+0x27c/0x1520 [ 9849.517003] ? lock_release+0x318/0x480 [ 9849.517220] ? __x64_sys_io_getevents+0x143/0x2d0 [ 9849.517479] ? percpu_ref_put_many.constprop.0+0x8f/0x210 [ 9849.517779] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 9849.518073] ? do_syscall_64+0x25e/0x1520 [ 9849.518291] ? __kasan_check_read+0x11/0x20 [ 9849.518519] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.518799] ? do_syscall_64+0x27c/0x1520 [ 9 ---truncated---

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call The multiple runs of generic/013 test-case is capable to reproduce a kernel BUG at mm/filemap.c:1504 with probability of 30%. while true; do sudo ./check generic/013 done [ 9849.452376] page: refcount:3 mapcount:0 mapping:00000000e58ff252 index:0x10781 pfn:0x1c322 [ 9849.452412] memcg:ffff8881a1915800 [ 9849.452417] aops:ceph_aops ino:1000058db9e dentry name(?):"f9XXXXXX" [ 9849.452432] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 9849.452441] raw: 0017ffffc0000000 0000000000000000 dead000000000122 ffff88816110d248 [ 9849.452445] raw: 0000000000010781 0000000000000000 00000003ffffffff ffff8881a1915800 [ 9849.452447] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) [ 9849.452474] ------------[ cut here ]------------ [ 9849.452476] kernel BUG at mm/filemap.c:1504! [ 9849.478635] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 9849.481772] CPU: 2 UID: 0 PID: 84223 Comm: fsstress Not tainted 7.0.0-rc1+ #18 PREEMPT(full) [ 9849.482881] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-9.fc43 06/1 0/2025 [ 9849.484539] RIP: 0010:folio_unlock+0x85/0xa0 [ 9849.485076] Code: 89 df 31 f6 e8 1c f3 ff ff 48 8b 5d f8 c9 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 48 c7 c6 80 6c d9 a7 48 89 df e8 4b b3 10 00 <0f> 0b 48 89 df e8 21 e6 2c 00 eb 9d 0f 1f 40 00 66 66 2e 0f 1f 84 [ 9849.493818] RSP: 0018:ffff8881bb8076b0 EFLAGS: 00010246 [ 9849.495740] RAX: 0000000000000000 RBX: ffffea00070c8980 RCX: 0000000000000000 [ 9849.498678] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 9849.500559] RBP: ffff8881bb8076b8 R08: 0000000000000000 R09: 0000000000000000 [ 9849.501097] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000010782000 [ 9849.502108] R13: ffff8881935de738 R14: ffff88816110d010 R15: 0000000000001000 [ 9849.502516] FS: 00007e36cbe94740(0000) GS:ffff88824a899000(0000) knlGS:0000000000000000 [ 9849.502996] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 9849.503810] CR2: 000000c0002b0000 CR3: 000000011bbf6004 CR4: 0000000000772ef0 [ 9849.504459] PKRU: 55555554 [ 9849.504626] Call Trace: [ 9849.505242] <TASK> [ 9849.505379] netfs_write_begin+0x7c8/0x10a0 [ 9849.505877] ? __kasan_check_read+0x11/0x20 [ 9849.506384] ? __pfx_netfs_write_begin+0x10/0x10 [ 9849.507178] ceph_write_begin+0x8c/0x1c0 [ 9849.507934] generic_perform_write+0x391/0x8f0 [ 9849.508503] ? __pfx_generic_perform_write+0x10/0x10 [ 9849.509062] ? file_update_time_flags+0x19a/0x4b0 [ 9849.509581] ? ceph_get_caps+0x63/0xf0 [ 9849.510259] ? ceph_get_caps+0x63/0xf0 [ 9849.510530] ceph_write_iter+0xe79/0x1ae0 [ 9849.511282] ? __pfx_ceph_write_iter+0x10/0x10 [ 9849.511839] ? lock_acquire+0x1ad/0x310 [ 9849.512334] ? ksys_write+0xf9/0x230 [ 9849.512582] ? lock_is_held_type+0xaa/0x140 [ 9849.513128] vfs_write+0x512/0x1110 [ 9849.513634] ? __fget_files+0x33/0x350 [ 9849.513893] ? __pfx_vfs_write+0x10/0x10 [ 9849.514143] ? mutex_lock_nested+0x1b/0x30 [ 9849.514394] ksys_write+0xf9/0x230 [ 9849.514621] ? __pfx_ksys_write+0x10/0x10 [ 9849.514887] ? do_syscall_64+0x25e/0x1520 [ 9849.515122] ? __kasan_check_read+0x11/0x20 [ 9849.515366] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.515655] __x64_sys_write+0x72/0xd0 [ 9849.515885] ? trace_hardirqs_on+0x24/0x1c0 [ 9849.516130] x64_sys_call+0x22f/0x2390 [ 9849.516341] do_syscall_64+0x12b/0x1520 [ 9849.516545] ? do_syscall_64+0x27c/0x1520 [ 9849.516783] ? do_syscall_64+0x27c/0x1520 [ 9849.517003] ? lock_release+0x318/0x480 [ 9849.517220] ? __x64_sys_io_getevents+0x143/0x2d0 [ 9849.517479] ? percpu_ref_put_many.constprop.0+0x8f/0x210 [ 9849.517779] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 9849.518073] ? do_syscall_64+0x25e/0x1520 [ 9849.518291] ? __kasan_check_read+0x11/0x20 [ 9849.518519] ? trace_hardirqs_on_prepare+0x178/0x1c0 [ 9849.518799] ? do_syscall_64+0x27c/0x1520 [ 9 ---truncated---

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration.
CWE not yet assigned
CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2403Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, möglicherweise Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen oder vertrauliche Informationen offenzulegen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260722Security Bulletin 22 Jul 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 22 Jul 2026, published on 22 July 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1252Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64056 Référence CVE CVE-2026-64057 https://www.cve.org/CVERecord?id=CVE-2026-64057 Référence CVE CVE-2026-64058 https://www.cve.org/CVERecord?id=CVE-2026-64058 Référence CVE CVE-2026-64059 https://www.cve.org/CVERecord?id=CVE-2026-64059 Référence CVE CVE-2026-64060 https://www.cve.org/CVERecord?id=CVE-2026-64060 Référence CVE CVE-2026-64061 https://www.cve.org/CVERecord?id=CVE-2026-64061 Référence CVE CVE-2026-64062 https://www.cve.org/CVERecord?id=CVE-2026-64062 Référence CVE CVE-2026-64063 https://www.cve.org/CVERecord?id=CVE-2026-64063 Référence CVE CVE-2026-64064 https://www.cve.org/CVERecord?id=CVE-2026-64064 Référence CVE CVE-2026-64065 https://www.cve.org/CVERecord?id=CVE-2026-64065 Référence CVE CVE-2026-64066 https://www.cve.org/CVERecord?id=CVE-2026-64066 Référence CVE CVE-2026-64067 https://www.cve.org/CVERecord?id=CVE-2026-64067 Référence CVE CVE-2026-64068 https://www.cve.org/CVERecord?id=CVE-2026-64068 Référence CVE CVE-2026-64069 https://www.cve.org/CVERecord?id=CVE-2026-64069 Référence CVE CVE-2026-64070 https://www.cve.org/CVERecord?id=CVE-2026-64070 Référence CVE CVE-2026-64071 https://www.cve.org/CVERecord?id=CVE-2026-64071 Référence CVE CVE-2026-64072 https://www.cve.org/CVERecord?id=CVE-2026-64072 Référence CVE CVE-2026-64073 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1229Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64056 Référence CVE CVE-2026-64057 https://www.cve.org/CVERecord?id=CVE-2026-64057 Référence CVE CVE-2026-64058 https://www.cve.org/CVERecord?id=CVE-2026-64058 Référence CVE CVE-2026-64059 https://www.cve.org/CVERecord?id=CVE-2026-64059 Référence CVE CVE-2026-64060 https://www.cve.org/CVERecord?id=CVE-2026-64060 Référence CVE CVE-2026-64061 https://www.cve.org/CVERecord?id=CVE-2026-64061 Référence CVE CVE-2026-64062 https://www.cve.org/CVERecord?id=CVE-2026-64062 Référence CVE CVE-2026-64063 https://www.cve.org/CVERecord?id=CVE-2026-64063 Référence CVE CVE-2026-64064 https://www.cve.org/CVERecord?id=CVE-2026-64064 Référence CVE CVE-2026-64065 https://www.cve.org/CVERecord?id=CVE-2026-64065 Référence CVE CVE-2026-64066 https://www.cve.org/CVERecord?id=CVE-2026-64066 Référence CVE CVE-2026-64067 https://www.cve.org/CVERecord?id=CVE-2026-64067 Référence CVE CVE-2026-64068 https://www.cve.org/CVERecord?id=CVE-2026-64068 Référence CVE CVE-2026-64069 https://www.cve.org/CVERecord?id=CVE-2026-64069 Référence CVE CVE-2026-64070 https://www.cve.org/CVERecord?id=CVE-2026-64070 Référence CVE CVE-2026-64071 https://www.cve.org/CVERecord?id=CVE-2026-64071 Référence CVE CVE-2026-64072 https://www.cve.org/CVERecord?id=CVE-2026-64072 Référence CVE CVE-2026-64073 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1162Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64056 Référence CVE CVE-2026-64057 https://www.cve.org/CVERecord?id=CVE-2026-64057 Référence CVE CVE-2026-64058 https://www.cve.org/CVERecord?id=CVE-2026-64058 Référence CVE CVE-2026-64059 https://www.cve.org/CVERecord?id=CVE-2026-64059 Référence CVE CVE-2026-64060 https://www.cve.org/CVERecord?id=CVE-2026-64060 Référence CVE CVE-2026-64061 https://www.cve.org/CVERecord?id=CVE-2026-64061 Référence CVE CVE-2026-64062 https://www.cve.org/CVERecord?id=CVE-2026-64062 Référence CVE CVE-2026-64063 https://www.cve.org/CVERecord?id=CVE-2026-64063 Référence CVE CVE-2026-64064 https://www.cve.org/CVERecord?id=CVE-2026-64064 Référence CVE CVE-2026-64065 https://www.cve.org/CVERecord?id=CVE-2026-64065 Référence CVE CVE-2026-64066 https://www.cve.org/CVERecord?id=CVE-2026-64066 Référence CVE CVE-2026-64067 https://www.cve.org/CVERecord?id=CVE-2026-64067 Référence CVE CVE-2026-64068 https://www.cve.org/CVERecord?id=CVE-2026-64068 Référence CVE CVE-2026-64069 https://www.cve.org/CVERecord?id=CVE-2026-64069 Référence CVE CVE-2026-64070 https://www.cve.org/CVERecord?id=CVE-2026-64070 Référence CVE CVE-2026-64071 https://www.cve.org/CVERecord?id=CVE-2026-64071 Référence CVE CVE-2026-64072 https://www.cve.org/CVERecord?id=CVE-2026-64072 Référence CVE CVE-2026-64073 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1066Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64056 Référence CVE CVE-2026-64057 https://www.cve.org/CVERecord?id=CVE-2026-64057 Référence CVE CVE-2026-64058 https://www.cve.org/CVERecord?id=CVE-2026-64058 Référence CVE CVE-2026-64059 https://www.cve.org/CVERecord?id=CVE-2026-64059 Référence CVE CVE-2026-64060 https://www.cve.org/CVERecord?id=CVE-2026-64060 Référence CVE CVE-2026-64061 https://www.cve.org/CVERecord?id=CVE-2026-64061 Référence CVE CVE-2026-64062 https://www.cve.org/CVERecord?id=CVE-2026-64062 Référence CVE CVE-2026-64063 https://www.cve.org/CVERecord?id=CVE-2026-64063 Référence CVE CVE-2026-64064 https://www.cve.org/CVERecord?id=CVE-2026-64064 Référence CVE CVE-2026-64065 https://www.cve.org/CVERecord?id=CVE-2026-64065 Référence CVE CVE-2026-64066 https://www.cve.org/CVERecord?id=CVE-2026-64066 Référence CVE CVE-2026-64067 https://www.cve.org/CVERecord?id=CVE-2026-64067 Référence CVE CVE-2026-64068 https://www.cve.org/CVERecord?id=CVE-2026-64068 Référence CVE CVE-2026-64069 https://www.cve.org/CVERecord?id=CVE-2026-64069 Référence CVE CVE-2026-64070 https://www.cve.org/CVERecord?id=CVE-2026-64070 Référence CVE CVE-2026-64071 https://www.cve.org/CVERecord?id=CVE-2026-64071 Référence CVE CVE-2026-64072 https://www.cve.org/CVERecord?id=CVE-2026-64072 Référence CVE CVE-2026-64073 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0954Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64056 Référence CVE CVE-2026-64057 https://www.cve.org/CVERecord?id=CVE-2026-64057 Référence CVE CVE-2026-64058 https://www.cve.org/CVERecord?id=CVE-2026-64058 Référence CVE CVE-2026-64059 https://www.cve.org/CVERecord?id=CVE-2026-64059 Référence CVE CVE-2026-64060 https://www.cve.org/CVERecord?id=CVE-2026-64060 Référence CVE CVE-2026-64061 https://www.cve.org/CVERecord?id=CVE-2026-64061 Référence CVE CVE-2026-64062 https://www.cve.org/CVERecord?id=CVE-2026-64062 Référence CVE CVE-2026-64063 https://www.cve.org/CVERecord?id=CVE-2026-64063 Référence CVE CVE-2026-64064 https://www.cve.org/CVERecord?id=CVE-2026-64064 Référence CVE CVE-2026-64065 https://www.cve.org/CVERecord?id=CVE-2026-64065 Référence CVE CVE-2026-64066 https://www.cve.org/CVERecord?id=CVE-2026-64066 Référence CVE CVE-2026-64067 https://www.cve.org/CVERecord?id=CVE-2026-64067 Référence CVE CVE-2026-64068 https://www.cve.org/CVERecord?id=CVE-2026-64068 Référence CVE CVE-2026-64069 https://www.cve.org/CVERecord?id=CVE-2026-64069 Référence CVE CVE-2026-64070 https://www.cve.org/CVERecord?id=CVE-2026-64070 Référence CVE CVE-2026-64071 https://www.cve.org/CVERecord?id=CVE-2026-64071 Référence CVE CVE-2026-64072 https://www.cve.org/CVERecord?id=CVE-2026-64072 Référence CVE CVE-2026-64073 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0926Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64056 Référence CVE CVE-2026-64057 https://www.cve.org/CVERecord?id=CVE-2026-64057 Référence CVE CVE-2026-64058 https://www.cve.org/CVERecord?id=CVE-2026-64058 Référence CVE CVE-2026-64059 https://www.cve.org/CVERecord?id=CVE-2026-64059 Référence CVE CVE-2026-64060 https://www.cve.org/CVERecord?id=CVE-2026-64060 Référence CVE CVE-2026-64061 https://www.cve.org/CVERecord?id=CVE-2026-64061 Référence CVE CVE-2026-64062 https://www.cve.org/CVERecord?id=CVE-2026-64062 Référence CVE CVE-2026-64063 https://www.cve.org/CVERecord?id=CVE-2026-64063 Référence CVE CVE-2026-64064 https://www.cve.org/CVERecord?id=CVE-2026-64064 Référence CVE CVE-2026-64065 https://www.cve.org/CVERecord?id=CVE-2026-64065 Référence CVE CVE-2026-64066 https://www.cve.org/CVERecord?id=CVE-2026-64066 Référence CVE CVE-2026-64067 https://www.cve.org/CVERecord?id=CVE-2026-64067 Référence CVE CVE-2026-64068 https://www.cve.org/CVERecord?id=CVE-2026-64068 Référence CVE CVE-2026-64069 https://www.cve.org/CVERecord?id=CVE-2026-64069 Référence CVE CVE-2026-64070 https://www.cve.org/CVERecord?id=CVE-2026-64070 Référence CVE CVE-2026-64071 https://www.cve.org/CVERecord?id=CVE-2026-64071 Référence CVE CVE-2026-64072 https://www.cve.org/CVERecord?id=CVE-2026-64072 Référence CVE CVE-2026-64073 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-031829LinuxのLinux Kernelにおける不特定の脆弱性

Linuxカーネルにおいて、以下の脆弱性が修正されました。netfs: netfs_write_begin()呼び出し内のVM_BUG_ON_FOLIO()問題の修正です。generic/013テストケースを複数回実行することで、mm/filemap.cの1504行目でカーネルBUGが30%の確率で再現されます。再現コマンド例は、while true; do sudo ./check generic/013; doneです。発生したBUGでは、ページ構造体の異常（VM_BUG_ON_FOLIO(!folio_test_locked(folio))）が検出され、カーネルはmm/filemap.cの1504行目で停止しました。詳細なコールトレースによると、netfs_write_beginやceph_write_begin、generic_perform_write、vfs_writeなど、ファイル書き込み処理に関連した関数が関与していました。この修正により、このBUGの発生を防止し、Linuxカーネルの安定性が向上しました。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix availability varies by product
Affected
Fixed
Linux: < 6.12, 6.12.92 ≤ 6.12.*, 6.18.34 ≤ 6.18.*, 7.0.11 ≤ 7.0.*, 7.1 ≤ *
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 19 Jul 2026 · Last source change 19 Jul 2026, 15:39 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-45638
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceUnavailable
NVD statusNVD enriched

Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: added patch: git.kernel.org/51ffb788f074c0a61953086f49008028c1e7b645; added patch: git.kernel.org/5ad05b6f5df296ef046589f222bb2587495b991e; 2 further additions.
    Before
    remediation: git.kernel.org/51ffb788f074c0a61953086f49008028c1e7b645
    After
    patch: git.kernel.org/51ffb788f074c0a61953086f49008028c1e7b645 · patch: git.kernel.org/5ad05b6f5df296ef046589f222bb2587495b991e · patch: git.kernel.org/b63971238beb79cf701dac33c6cefc56c07c89fa · 2 more references
    git.kernel.org ↗
  2. SeveritySeverity changed from Unknown to Medium.
    Before
    Unknown
    After
    Medium
    NIST NVD ↗
  3. CVSS scoreCVSS score changed from not recorded to 5.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
    Before
    not recorded
    After
    5.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
    NIST NVD ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-45638↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Patch or update reference↗Patch or update reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-64065 · cve.blacktree.nl