CVE-2026-46173
HighIn 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)
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected versions
Linux kernel versions
5.17
and later are affected. Fixed in
6.1.175,
6.6.140,
6.12.88,
6.18.30,
7.0.7,
7.1-rc4
and their respective stable series.
References
The following references provide additional information about CVE-2026-46173 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/3d6fb8a7690c23e3213c4b008f64d89a44b98737
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PatchKernel patch commithttps://git.kernel.org/stable/c/640b4c00fb0e2920327435f6176cbefc3c546165
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PatchKernel patch commithttps://git.kernel.org/stable/c/6f49f94f3b11fe8bff1bf2a054143789e76aaf17
Frequently asked questions
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What is CVE-2026-46173?
CVE-2026-46173 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 5.17 onward and has been patched in 6.1.175, 6.6.140, 6.12.88 and others. CVE-2026-46173 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-46173?
CVE-2026-46173 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2026-46173?
Yes — CVE-2026-46173 has been patched. Fixed versions include 6.1.175, 6.6.140, 6.12.88 and others. If you are running Linux kernel 5.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-46173 actively exploited?
No — CVE-2026-46173 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.