CVE-2026-31554: Linux kernel · futex: Require sys_futex_requeue() to have identical flags
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e2f78c7ec1655fedd945366151ba54fcb9580508 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% 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 e2f78c7ec1655fedd945366151ba54fcb9580508, 027145ace09fad4c7cbcd6c61fe9b429c63eb0e5, 19f94b39058681dec64a10ebeb6f23fe7fc3f77a +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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
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 Linux kernel to e2f78c7ec1655fedd945366151ba54fcb9580508, 027145ace09fad4c7cbcd6c61fe9b429c63eb0e5, 19f94b39058681dec64a10ebeb6f23fe7fc3f77a or 18b7d09c2b794c71d4252f3ea2cf84ad12b73d6a.
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– |
AI-suggested
A fix for this vulnerability has been implemented and is available in the Linux kernel source code as indicated by the fixed commit hashes. Users and administrators should update their Linux kernel to a version that includes these fixes to mitigate the vulnerability. Since this is not a cloud service, manual patching is required. There are no indications of active exploitation in the wild.
Description
CVE-2026-31554 is a high-severity vulnerability in the Linux kernel's futex subsystem. It involves the sys_futex_requeue() system call, which previously allowed different flags to be used, potentially leading to a use-after-free (UaF) condition. The vulnerability has been resolved by requiring sys_futex_requeue() to have identical flags, aligning with the behavior of older sys_futex() requeue operations. This fix prevents the exploitation of the UaF condition. The vulnerability affects Linux kernel version 6.7.
References
- git.kernel.org/stable/c/027145ace09fad4c7cbcd6c61fe9b429c63eb0e5 (opens in a new tab)
- git.kernel.org/stable/c/18b7d09c2b794c71d4252f3ea2cf84ad12b73d6a (opens in a new tab)
- git.kernel.org/stable/c/e2f78c7ec1655fedd945366151ba54fcb9580508 (opens in a new tab)
- git.kernel.org/stable/c/19f94b39058681dec64a10ebeb6f23fe7fc3f77a (opens in a new tab)