CVE-2026-31446: Linux kernel · Use After Free
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in d15e4b0a418537aafa56b2cb80d44add83e83697 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% 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 d15e4b0a418537aafa56b2cb80d44add83e83697, c97e282f7bfd0c3554c63d289964a5ca6a1d2ffe, c8fe17a1b308c3d8c703ebfb049b325f844342c3 +7
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 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 to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix for this vulnerability is available and has been incorporated into Linux kernel versions 5.11, 5.15.203, 5.18, and later. Users and administrators should update to these fixed versions or later to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-31446 is a use-after-free vulnerability in the ext4 filesystem code of the Linux kernel. It occurs in the update_super_work function when racing with the unmount operation, due to improper handling of sysfs teardown and notification calls. The flaw was introduced by a commit that reordered ext4_unregister_sysfs() calls, leading to a stale pointer dereference. The issue is fixed by adding a check to avoid sysfs_notify() if sysfs has already been torn down and by serializing access with a mutex to prevent race conditions.
References
- git.kernel.org/stable/c/c8fe17a1b308c3d8c703ebfb049b325f844342c3 (opens in a new tab)
- git.kernel.org/stable/c/c4d829737329f2290dd41e290b7d75effdb2a7ff (opens in a new tab)
- git.kernel.org/stable/c/9449f99ba04f5dd1c8423ad8a90b3651d7240d1d (opens in a new tab)
- git.kernel.org/stable/c/034053378dd81837fd6c7a43b37ee2e58d4f0b4e (opens in a new tab)
- git.kernel.org/stable/c/c97e282f7bfd0c3554c63d289964a5ca6a1d2ffe (opens in a new tab)
- git.kernel.org/stable/c/08b10e6f37fc533a759e9833af0692242e8b3f93 (opens in a new tab)
- git.kernel.org/stable/c/d15e4b0a418537aafa56b2cb80d44add83e83697 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-082556.html (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)