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Full vulnerability report · 2026
CVE-2026-64453High confidence

usb: misc: usbio: fix disconnect UAF in client teardown

Linux · Linux

7.8HighCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. 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 severityHighOperational priority:Medium, lowered one band.downgradedsince 17 Aug 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.17% 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: As exposure requiresRemediation target: Within 365 days

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 · sourcelinuxNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcelinuxNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.7.1.4-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.7.1.4-1Debian Security Tracker ↗Source updated 5 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-2026-64453 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykernel: usb: misc: usbio: fix disconnect UAF in client teardown
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 USB subsystem, specifically within the `usbio` module. This vulnerability, known as a use-after-free (UAF), occurs when the system attempts to access memory that has already been released during the disconnection of a USB device. A local attacker or a specially crafted malicious USB device could exploit this flaw. Successful exploitation could lead to a system crash (denial of service) or potentially allow for the execution of unauthorized code.
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-2026-48797

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

High technical severity; prioritise exposed affected systems while verifying vendor guidance. 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: usb: misc: usbio: fix disconnect UAF in client teardown usbio_disconnect() walks usbio->cli_list in reverse and uninitializes each auxiliary device. auxiliary_device_uninit() drops the device reference, and for an unbound child that can run usbio_auxdev_release() and free the containing struct usbio_client. list_for_each_entry_reverse() advances after the loop body by reading client->link.prev. If the current client is freed by auxiliary_device_uninit(), the iterator dereferences freed memory. Use list_for_each_entry_safe_reverse() so the previous client is cached before the body can drop the final reference. This preserves reverse teardown order while keeping the next iterator cursor independent of the current client's lifetime. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150 Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? usbio_disconnect+0x12e/0x150 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x188/0x320 ? usbio_disconnect+0x12e/0x150 kasan_report+0xe0/0x110 ? usbio_disconnect+0x12e/0x150 usbio_disconnect+0x12e/0x150 usb_unbind_interface+0xf3/0x400 really_probe+0x316/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x44/0x60 ? srso_alias_return_thunk+0x5/0xfbef5 ? lockdep_hardirqs_on_prepare+0xea/0x1a0 ? srso_alias_return_thunk+0x5/0xfbef5 ? usb_enable_lpm+0x3c/0x260 usb_set_configuration+0xb64/0xf20 usb_generic_driver_probe+0x5f/0x90 usb_probe_device+0x71/0x1b0 really_probe+0x46b/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? add_device_randomness+0xb7/0xf0 usb_new_device+0x492/0x870 hub_event+0x1b10/0x29c0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x187/0x300 ? process_one_work+0x475/0xb90 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_release+0xc8/0x290 ? srso_alias_return_thunk+0x5/0xfbef5 process_one_work+0x4d7/0xb90 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>

What

In the Linux kernel, the following vulnerability has been resolved: usb: misc: usbio: fix disconnect UAF in client teardown usbio_disconnect() walks usbio->cli_list in reverse and uninitializes each auxiliary device. auxiliary_device_uninit() drops the device reference, and for an unbound child that can run usbio_auxdev_release() and free the containing struct usbio_client. list_for_each_entry_reverse() advances after the loop body by reading client->link.prev. If the current client is freed by auxiliary_device_uninit(), the iterator dereferences freed memory. Use list_for_each_entry_safe_reverse() so the previous client is cached before the body can drop the final reference. This preserves reverse teardown order while keeping the next iterator cursor independent of the current client's lifetime. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150 Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? usbio_disconnect+0x12e/0x150 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x188/0x320 ? usbio_disconnect+0x12e/0x150 kasan_report+0xe0/0x110 ? usbio_disconnect+0x12e/0x150 usbio_disconnect+0x12e/0x150 usb_unbind_interface+0xf3/0x400 really_probe+0x316/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x44/0x60 ? srso_alias_return_thunk+0x5/0xfbef5 ? lockdep_hardirqs_on_prepare+0xea/0x1a0 ? srso_alias_return_thunk+0x5/0xfbef5 ? usb_enable_lpm+0x3c/0x260 usb_set_configuration+0xb64/0xf20 usb_generic_driver_probe+0x5f/0x90 usb_probe_device+0x71/0x1b0 really_probe+0x46b/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? add_device_randomness+0xb7/0xf0 usb_new_device+0x492/0x870 hub_event+0x1b10/0x29c0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x187/0x300 ? process_one_work+0x475/0xb90 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_release+0xc8/0x290 ? srso_alias_return_thunk+0x5/0xfbef5 process_one_work+0x4d7/0xb90 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

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: usb: misc: usbio: fix disconnect UAF in client teardown usbio_disconnect() walks usbio->cli_list in reverse and uninitializes each auxiliary device. auxiliary_device_uninit() drops the device reference, and for an unbound child that can run usbio_auxdev_release() and free the containing struct usbio_client. list_for_each_entry_reverse() advances after the loop body by reading client->link.prev. If the current client is freed by auxiliary_device_uninit(), the iterator dereferences freed memory. Use list_for_each_entry_safe_reverse() so the previous client is cached before the body can drop the final reference. This preserves reverse teardown order while keeping the next iterator cursor independent of the current client's lifetime. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150 Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? usbio_disconnect+0x12e/0x150 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x188/0x320 ? usbio_disconnect+0x12e/0x150 kasan_report+0xe0/0x110 ? usbio_disconnect+0x12e/0x150 usbio_disconnect+0x12e/0x150 usb_unbind_interface+0xf3/0x400 really_probe+0x316/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x44/0x60 ? srso_alias_return_thunk+0x5/0xfbef5 ? lockdep_hardirqs_on_prepare+0xea/0x1a0 ? srso_alias_return_thunk+0x5/0xfbef5 ? usb_enable_lpm+0x3c/0x260 usb_set_configuration+0xb64/0xf20 usb_generic_driver_probe+0x5f/0x90 usb_probe_device+0x71/0x1b0 really_probe+0x46b/0x660 __driver_probe_device+0x106/0x240 driver_probe_device+0x4a/0x110 __device_attach_driver+0xf1/0x1a0 ? __pfx___device_attach_driver+0x10/0x10 bus_for_each_drv+0xf9/0x160 ? __pfx_bus_for_each_drv+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? trace_hardirqs_on+0x18/0x130 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __device_attach+0x133/0x2a0 ? __pfx___device_attach+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? do_raw_spin_unlock+0x9a/0x100 ? srso_alias_return_thunk+0x5/0xfbef5 device_initial_probe+0x55/0x70 bus_probe_device+0x4a/0xd0 device_add+0x9b9/0xc10 ? __pfx_device_add+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? add_device_randomness+0xb7/0xf0 usb_new_device+0x492/0x870 hub_event+0x1b10/0x29c0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x187/0x300 ? process_one_work+0x475/0xb90 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_release+0xc8/0x290 ? srso_alias_return_thunk+0x5/0xfbef5 process_one_work+0x4d7/0xb90 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_hub_event+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

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 → Use After Free → 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: a standard category for the underlying weakness.
CWE-416 ↗

CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

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:H/I:H/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.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.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.
CWE-416
A

Official authority intelligence

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

BSI · German · WID-SEC-2026-2527Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um nicht näher spezifizierte Angriffe durchzuführen, dazu können DoS-Angriffe, die Offenlegung von Informationen, die Beschädigung des Speichers oder die Umgehung von Sicherheitsmaßnahmen gehören.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260729Security Bulletin 29 Jul 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 29 Jul 2026, published on 29 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-2026-64444 Référence CVE CVE-2026-64445 https://www.cve.org/CVERecord?id=CVE-2026-64445 Référence CVE CVE-2026-64446 https://www.cve.org/CVERecord?id=CVE-2026-64446 Référence CVE CVE-2026-64447 https://www.cve.org/CVERecord?id=CVE-2026-64447 Référence CVE CVE-2026-64448 https://www.cve.org/CVERecord?id=CVE-2026-64448 Référence CVE CVE-2026-64449 https://www.cve.org/CVERecord?id=CVE-2026-64449 Référence CVE CVE-2026-64450 https://www.cve.org/CVERecord?id=CVE-2026-64450 Référence CVE CVE-2026-64451 https://www.cve.org/CVERecord?id=CVE-2026-64451 Référence CVE CVE-2026-64452 https://www.cve.org/CVERecord?id=CVE-2026-64452 Référence CVE CVE-2026-64453 https://www.cve.org/CVERecord?id=CVE-2026-64453 Référence CVE CVE-2026-64454 https://www.cve.org/CVERecord?id=CVE-2026-64454 Référence CVE CVE-2026-64455 https://www.cve.org/CVERecord?id=CVE-2026-64455 Référence CVE CVE-2026-64456 https://www.cve.org/CVERecord?id=CVE-2026-64456 Référence CVE CVE-2026-64457 https://www.cve.org/CVERecord?id=CVE-2026-64457 Référence CVE CVE-2026-64458 https://www.cve.org/CVERecord?id=CVE-2026-64458 Référence CVE CVE-2026-64459 https://www.cve.org/CVERecord?id=CVE-2026-64459 Référence CVE CVE-2026-64460 https://www.cve.org/CVERecord?id=CVE-2026-64460 Référence CVE CVE-2026-64461 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-2026-64444 Référence CVE CVE-2026-64445 https://www.cve.org/CVERecord?id=CVE-2026-64445 Référence CVE CVE-2026-64446 https://www.cve.org/CVERecord?id=CVE-2026-64446 Référence CVE CVE-2026-64447 https://www.cve.org/CVERecord?id=CVE-2026-64447 Référence CVE CVE-2026-64448 https://www.cve.org/CVERecord?id=CVE-2026-64448 Référence CVE CVE-2026-64449 https://www.cve.org/CVERecord?id=CVE-2026-64449 Référence CVE CVE-2026-64450 https://www.cve.org/CVERecord?id=CVE-2026-64450 Référence CVE CVE-2026-64451 https://www.cve.org/CVERecord?id=CVE-2026-64451 Référence CVE CVE-2026-64452 https://www.cve.org/CVERecord?id=CVE-2026-64452 Référence CVE CVE-2026-64453 https://www.cve.org/CVERecord?id=CVE-2026-64453 Référence CVE CVE-2026-64454 https://www.cve.org/CVERecord?id=CVE-2026-64454 Référence CVE CVE-2026-64455 https://www.cve.org/CVERecord?id=CVE-2026-64455 Référence CVE CVE-2026-64456 https://www.cve.org/CVERecord?id=CVE-2026-64456 Référence CVE CVE-2026-64457 https://www.cve.org/CVERecord?id=CVE-2026-64457 Référence CVE CVE-2026-64458 https://www.cve.org/CVERecord?id=CVE-2026-64458 Référence CVE CVE-2026-64459 https://www.cve.org/CVERecord?id=CVE-2026-64459 Référence CVE CVE-2026-64460 https://www.cve.org/CVERecord?id=CVE-2026-64460 Référence CVE CVE-2026-64461 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1203Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2026-64444 Référence CVE CVE-2026-64445 https://www.cve.org/CVERecord?id=CVE-2026-64445 Référence CVE CVE-2026-64446 https://www.cve.org/CVERecord?id=CVE-2026-64446 Référence CVE CVE-2026-64447 https://www.cve.org/CVERecord?id=CVE-2026-64447 Référence CVE CVE-2026-64448 https://www.cve.org/CVERecord?id=CVE-2026-64448 Référence CVE CVE-2026-64449 https://www.cve.org/CVERecord?id=CVE-2026-64449 Référence CVE CVE-2026-64450 https://www.cve.org/CVERecord?id=CVE-2026-64450 Référence CVE CVE-2026-64451 https://www.cve.org/CVERecord?id=CVE-2026-64451 Référence CVE CVE-2026-64452 https://www.cve.org/CVERecord?id=CVE-2026-64452 Référence CVE CVE-2026-64453 https://www.cve.org/CVERecord?id=CVE-2026-64453 Référence CVE CVE-2026-64454 https://www.cve.org/CVERecord?id=CVE-2026-64454 Référence CVE CVE-2026-64455 https://www.cve.org/CVERecord?id=CVE-2026-64455 Référence CVE CVE-2026-64456 https://www.cve.org/CVERecord?id=CVE-2026-64456 Référence CVE CVE-2026-64457 https://www.cve.org/CVERecord?id=CVE-2026-64457 Référence CVE CVE-2026-64458 https://www.cve.org/CVERecord?id=CVE-2026-64458 Référence CVE CVE-2026-64459 https://www.cve.org/CVERecord?id=CVE-2026-64459 Référence CVE CVE-2026-64460 https://www.cve.org/CVERecord?id=CVE-2026-64460 Référence CVE CVE-2026-64461 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-2026-64444 Référence CVE CVE-2026-64445 https://www.cve.org/CVERecord?id=CVE-2026-64445 Référence CVE CVE-2026-64446 https://www.cve.org/CVERecord?id=CVE-2026-64446 Référence CVE CVE-2026-64447 https://www.cve.org/CVERecord?id=CVE-2026-64447 Référence CVE CVE-2026-64448 https://www.cve.org/CVERecord?id=CVE-2026-64448 Référence CVE CVE-2026-64449 https://www.cve.org/CVERecord?id=CVE-2026-64449 Référence CVE CVE-2026-64450 https://www.cve.org/CVERecord?id=CVE-2026-64450 Référence CVE CVE-2026-64451 https://www.cve.org/CVERecord?id=CVE-2026-64451 Référence CVE CVE-2026-64452 https://www.cve.org/CVERecord?id=CVE-2026-64452 Référence CVE CVE-2026-64453 https://www.cve.org/CVERecord?id=CVE-2026-64453 Référence CVE CVE-2026-64454 https://www.cve.org/CVERecord?id=CVE-2026-64454 Référence CVE CVE-2026-64455 https://www.cve.org/CVERecord?id=CVE-2026-64455 Référence CVE CVE-2026-64456 https://www.cve.org/CVERecord?id=CVE-2026-64456 Référence CVE CVE-2026-64457 https://www.cve.org/CVERecord?id=CVE-2026-64457 Référence CVE CVE-2026-64458 https://www.cve.org/CVERecord?id=CVE-2026-64458 Référence CVE CVE-2026-64459 https://www.cve.org/CVERecord?id=CVE-2026-64459 Référence CVE CVE-2026-64460 https://www.cve.org/CVERecord?id=CVE-2026-64460 Référence CVE CVE-2026-64461 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-031999LinuxのLinux Kernelにおける解放済みメモリの使用に関する脆弱性

Linuxカーネルにおいて、以下の脆弱性が修正されました。usb: misc: usbioに関する問題で、クライアントの終了処理時に発生する切断後使用（Use-After-Free、UAF）に関する修正です。usbio_disconnect()はusbio-＞cli_listを逆方向にたどりながら、各補助デバイスを非初期化します。auxiliary_device_uninit()はデバイス参照を解放し、未バインドの子デバイスであればusbio_auxdev_release()を実行してusbio_client構造体を解放することがあります。list_for_each_entry_reverse()はループ本体の後にclient-＞link.prevを読み込んで次の要素に進みます。しかし、現在のclientがauxiliary_device_uninit()によって解放されると、イテレーターは解放済みのメモリを逆参照してしまいます。そこでlist_for_each_entry_safe_reverse()を使用し、ループ本体が最後の参照を解放する前に前のclientをキャッシュしています。これにより逆順での終了処理の順序を保持しつつ、次のイテレーターのカーソルが現在のclientの生存期間に依存しない形にしています。検証では以下のカーネルレポートが再現されました。BUG: KASAN: slab-use-after-free in usbio_disconnect+0x12e/0x150（中略）。この修正により、usbio_disconnect関数中の使用後解放エラーの発生が防止されています。

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: < 6.18, 6.18.39 ≤ 6.18.*, 7.1.4 ≤ 7.1.*, 7.2 ≤ *
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 25 Jul 2026 · Last source change 17 Aug 2026, 04:55 UTC · CWE-416 · Use After Free

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-2026-48797
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceNIST NVD
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed: added patch: git.kernel.org/0bfeec21984fedd32987f4e4c0cde34b445af404; added patch: git.kernel.org/1947b6411460d68b54b13c536961933166937d05; 1 further additions.
    Before
    remediation: git.kernel.org/c40090f8d19b415e2925b22be964b5d1f695666f
    After
    patch: git.kernel.org/0bfeec21984fedd32987f4e4c0cde34b445af404 · patch: git.kernel.org/1947b6411460d68b54b13c536961933166937d05 · patch: git.kernel.org/c40090f8d19b415e2925b22be964b5d1f695666f · 1 more references
    git.kernel.org ↗
  2. SeveritySeverity changed from Unknown to High.
    Before
    Unknown
    After
    High
    NIST NVD ↗
  3. CVSS scoreCVSS score changed from not recorded to 7.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
    Before
    not recorded
    After
    7.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
    NIST NVD ↗
  4. Affected versionsThe structured affected or fixed version information changed.
    Before
    121a0f839dbb397af5fabb701cea3e9983223e50 < c40090f8d19b415e2925b22be964b5d1f695666f; 121a0f839dbb397af5fabb701cea3e9983223e50 < 1947b6411460d68b54b13c536961933166937d05; 121a0f839dbb397af5fabb701cea3e9983223e50 < 0bfeec21984fedd32987f4e4c0cde34b445af404; 6.18 · Fixed: < 6.18; 6.18.39 ≤ 6.18.*; 7.1.4 ≤ 7.1.*; 7.2-rc3 ≤ *
    After
    121a0f839dbb397af5fabb701cea3e9983223e50 < c40090f8d19b415e2925b22be964b5d1f695666f; 121a0f839dbb397af5fabb701cea3e9983223e50 < 1947b6411460d68b54b13c536961933166937d05; 121a0f839dbb397af5fabb701cea3e9983223e50 < 0bfeec21984fedd32987f4e4c0cde34b445af404; 6.18 · Fixed: < 6.18; 6.18.39 ≤ 6.18.*; 7.1.4 ≤ 7.1.*; 7.2 ≤ *
    CNA ↗
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-2026-48797↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor 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-2026-64453 · cve.blacktree.nl