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VulnerabilityPublished Updated

CVE-2026-46173: Linux kernel · exit: prevent preemption of oopsing TASK_DEAD task

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891, 9756b3db5db6c2f5eccb32dddbd88eb4c54f575e, 640b4c00fb0e2920327435f6176cbefc3c546165 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 7f80a2fd7db9a55894fd841915236aca611291b5, < c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891
Fixed in
  • c1fa0bb633e4a6b11e83ffc57fa5abe8ebb87891
LinuxLinuxAffected
  • ≥ 7f80a2fd7db9a55894fd841915236aca611291b5, < 9756b3db5db6c2f5eccb32dddbd88eb4c54f575e
Fixed in
  • 9756b3db5db6c2f5eccb32dddbd88eb4c54f575e
LinuxLinuxAffected
  • ≥ 7f80a2fd7db9a55894fd841915236aca611291b5, < 640b4c00fb0e2920327435f6176cbefc3c546165
Fixed in
  • 640b4c00fb0e2920327435f6176cbefc3c546165
LinuxLinuxAffected
  • ≥ 7f80a2fd7db9a55894fd841915236aca611291b5, < 7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34
Fixed in
  • 7b2800ba5f5f77a8ee7f4cbadb19cf1264597a34
LinuxLinuxAffected
  • ≥ 7f80a2fd7db9a55894fd841915236aca611291b5, < 6f49f94f3b11fe8bff1bf2a054143789e76aaf17
Fixed in
  • 6f49f94f3b11fe8bff1bf2a054143789e76aaf17
LinuxLinuxAffected
  • ≥ 7f80a2fd7db9a55894fd841915236aca611291b5, < 3d6fb8a7690c23e3213c4b008f64d89a44b98737
Fixed in
  • 3d6fb8a7690c23e3213c4b008f64d89a44b98737

Description

In the Linux kernel, the following vulnerability has been resolved: exit: prevent preemption of oopsing TASK_DEAD task When an already-exiting task oopses, make_task_dead() currently calls do_task_dead() with preemption enabled. That is forbidden: do_task_dead() calls __schedule(), which has a comment saying "WARNING: must be called with preemption disabled!". If an oopsing task is preempted in do_task_dead(), between becoming TASK_DEAD and entering the scheduler explicitly, bad things happen: finish_task_switch() assumes that once the scheduler has switched away from a TASK_DEAD task, the task can never run again and its stack is no longer needed; but that assumption apparently doesn't hold if the dead task was preempted (the SM_PREEMPT case). This means that the scheduler ends up repeatedly dropping references on the dead task's stack, which can lead to use-after-free or double-free of the entire task stack; in other words, two tasks can end up running on the same stack, resulting in various kinds of memory corruption. (This does not just affect "recursively oopsing" tasks; it is enough to oops once during task exit, for example in a file_operations::release handler)

References

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