CVE-2026-43499
HighIn the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]
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
2.6.39
and later are affected. Fixed in
6.1.175,
6.6.140,
6.12.86,
6.18.27,
7.0.4,
7.1-rc1
and their respective stable series.
References
The following references provide additional information about CVE-2026-43499 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
-
PatchKernel patch commithttps://git.kernel.org/stable/c/3bfdc63936dd4773109b7b8c280c0f3b5ae7d349
-
PatchKernel patch commithttps://git.kernel.org/stable/c/3fb7394a837740770f0d6b4b30567e60786a63f2
-
PatchKernel patch commithttps://git.kernel.org/stable/c/6d52dfcb2a5db86e346cf51f8fcf2071b8085166
Frequently asked questions
-
What is CVE-2026-43499?
CVE-2026-43499 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 2.6.39 onward and has been patched in 6.1.175, 6.6.140, 6.12.86 and others. CVE-2026-43499 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
What is the CVSS score for CVE-2026-43499?
CVE-2026-43499 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-2026-43499?
Yes — CVE-2026-43499 has been patched. Fixed versions include 6.1.175, 6.6.140, 6.12.86 and others. If you are running Linux kernel 2.6.39 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-43499 actively exploited?
No — CVE-2026-43499 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.