Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.22% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2025
CVE-2025-38194High confidence
jffs2: check that raw node were preallocated before writing summary
Linux · Linux
5.5MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium 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 21 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Low, lowered one band.downgradedsince 11 May 2026
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
- Confirm that the asset runs Linux Linux and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 21 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Canonical Ubuntu Security: 21 affected package states with no published fix
Distribution package intelligence
25 package statesRelease-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.
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 21 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 release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.12.35-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian bookwormbookworm · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.147-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian forkyforky · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.12.35-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian sidsid · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.12.35-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-aws | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-azure | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-azure-fde | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-azure-nvidia | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-gcp | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-gke | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-gkeop | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-ibm | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-intel | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-lowlatency | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-nvidia | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-nvidia-lowlatency | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-nvidia-tegra | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-oem-6.11 | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-oracle | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-raspi | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-raspi-realtime | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-realtime | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-riscv | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-xilinx | Affected, 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 feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
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 21 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
In the Linux kernel, the following vulnerability has been resolved: jffs2: check that raw node were preallocated before writing summary Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't check return value of jffs2_prealloc_raw_node_refs and simply lets any error propagate into jffs2_sum_write_data, which eventually calls jffs2_link_node_ref in order to link the summary to an expectedly allocated node. kernel BUG at fs/jffs2/nodelist.c:592! invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592 Call Trace: <TASK> jffs2_sum_write_data fs/jffs2/summary.c:841 [inline] jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005 call_write_iter include/linux/fs.h:2265 [inline] do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735 do_iter_write+0x186/0x710 fs/read_write.c:861 vfs_iter_write+0x70/0xa0 fs/read_write.c:902 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0x10c/0x170 fs/splice.c:950 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896 do_splice_direct+0x1a9/0x280 fs/splice.c:1002 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Fix this issue by checking return value of jffs2_prealloc_raw_node_refs before calling jffs2_sum_write_data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
What
In the Linux kernel, the following vulnerability has been resolved: jffs2: check that raw node were preallocated before writing summary Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't check return value of jffs2_prealloc_raw_node_refs and simply lets any error propagate into jffs2_sum_write_data, which eventually calls jffs2_link_node_ref in order to link the summary to an expectedly allocated node. kernel BUG at fs/jffs2/nodelist.c:592! invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592 Call Trace: <TASK> jffs2_sum_write_data fs/jffs2/summary.c:841 [inline] jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005 call_write_iter include/linux/fs.h:2265 [inline] do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735 do_iter_write+0x186/0x710 fs/read_write.c:861 vfs_iter_write+0x70/0xa0 fs/read_write.c:902 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0x10c/0x170 fs/splice.c:950 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896 do_splice_direct+0x1a9/0x280 fs/splice.c:1002 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Fix this issue by checking return value of jffs2_prealloc_raw_node_refs before calling jffs2_sum_write_data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
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: jffs2: check that raw node were preallocated before writing summary Syzkaller detected a kernel bug in jffs2_link_node_ref, caused by fault injection in jffs2_prealloc_raw_node_refs. jffs2_sum_write_sumnode doesn't check return value of jffs2_prealloc_raw_node_refs and simply lets any error propagate into jffs2_sum_write_data, which eventually calls jffs2_link_node_ref in order to link the summary to an expectedly allocated node. kernel BUG at fs/jffs2/nodelist.c:592! invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 31277 Comm: syz-executor.7 Not tainted 6.1.128-syzkaller-00139-ge10f83ca10a1 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0x570/0x690 fs/jffs2/nodelist.c:592 Call Trace: <TASK> jffs2_sum_write_data fs/jffs2/summary.c:841 [inline] jffs2_sum_write_sumnode+0xd1a/0x1da0 fs/jffs2/summary.c:874 jffs2_do_reserve_space+0xa18/0xd60 fs/jffs2/nodemgmt.c:388 jffs2_reserve_space+0x55f/0xaa0 fs/jffs2/nodemgmt.c:197 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x726/0x15d0 fs/jffs2/file.c:301 generic_perform_write+0x314/0x5d0 mm/filemap.c:3856 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3973 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4005 call_write_iter include/linux/fs.h:2265 [inline] do_iter_readv_writev+0x20f/0x3c0 fs/read_write.c:735 do_iter_write+0x186/0x710 fs/read_write.c:861 vfs_iter_write+0x70/0xa0 fs/read_write.c:902 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0x10c/0x170 fs/splice.c:950 splice_direct_to_actor+0x337/0xa10 fs/splice.c:896 do_splice_direct+0x1a9/0x280 fs/splice.c:1002 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Fix this issue by checking return value of jffs2_prealloc_raw_node_refs before calling jffs2_sum_write_data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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:HCommon 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.
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
- 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 4 Jul 2025 · Last source change 11 May 2026, 21:23 UTC · CWE not yet assigned
CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2025-20062
Product sourceCNA
Remediation sourceCVE/CNA references
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
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
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.