CVE-2026-43499: Linux kernel · rtmutex: Use waiter::task instead of current in remove_waiter()
Affects Linux kernelSource CVE Database V5
Public exploit available · CVSS 7.8 High · fixed in f3fa3424bceb128d2be4b3745506b22844b87db7 : patch Linux kernel as a priority.
Data as of 10 Nov 2026, 13:05 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- 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, 2026-08-22.
- Patch
- Available – fixed in f3fa3424bceb128d2be4b3745506b22844b87db7, d8cce4773c2b23d819baf5abedc62f7b430e8745, 88614876370aac8ad1050ad785a4c095ba17ac11 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 21 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by kernel.org
, 20 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 93 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
This vulnerability has been fixed in multiple Linux kernel commits following version 2.6.39. Users and administrators should upgrade to a Linux kernel version that includes these fixes. Since this is not a cloud service, manual patching or kernel upgrade is required. There are no vendor advisories indicating that no action is needed or that the issue is already mitigated otherwise.
Description
CVE-2026-43499 is a high-severity vulnerability in the Linux kernel's real-time mutex (rtmutex) implementation. The flaw involves the remove_waiter() function incorrectly using the current task instead of the waiter::task for certain operations, leading to issues such as improper locking, dangling pointers, and incorrect priority adjustments. This vulnerability affects Linux kernel version 2.6.39 and has been fixed in subsequent commits.
References
- git.kernel.org/stable/c/f3fa3424bceb128d2be4b3745506b22844b87db7 (opens in a new tab)
- git.kernel.org/stable/c/838ce5cb5d93c3ab8b27e75bc6ad905a94b752fd (opens in a new tab)
- git.kernel.org/stable/c/d8cce4773c2b23d819baf5abedc62f7b430e8745 (opens in a new tab)
- git.kernel.org/stable/c/8a1fc8d698ac5e5916e3082a0f74450d71f9611f (opens in a new tab)
- git.kernel.org/stable/c/6d52dfcb2a5db86e346cf51f8fcf2071b8085166 (opens in a new tab)
- git.kernel.org/stable/c/3fb7394a837740770f0d6b4b30567e60786a63f2 (opens in a new tab)
- git.kernel.org/stable/c/88614876370aac8ad1050ad785a4c095ba17ac11 (opens in a new tab)
- git.kernel.org/stable/c/3bfdc63936dd4773109b7b8c280c0f3b5ae7d349 (opens in a new tab)
- openwall.com/lists/oss-security/2026/07/08/12 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)