CVE-2026-23413: Linux kernel · clsact: Fix use-after-free in init/destroy rollback asymmetry
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in a0671125d4f55e1e98d9bde8a0b671941987e208 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% 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 a0671125d4f55e1e98d9bde8a0b671941987e208, a73d95b57bf9faebdfed591bcb7ed9292062a84c, 0509b762bc5e8ea7b8391130730c6d8502fc6e69 +4
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 2 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 6.6.130, 6.10, and associated commits. Users and administrators should update affected Linux kernel versions to these fixed releases to remediate the issue. No additional mitigation steps are indicated beyond applying the official patches.
Description
CVE-2026-23413 is a use-after-free vulnerability in the Linux kernel's clsact qdisc component. The flaw arises from an asymmetry in initialization and destruction rollback, where a failure during the replacement of a clsact instance can lead to premature release of resources. This issue has been fixed by improving checks on whether ingress or egress sides were properly initialized before destruction.
References
- git.kernel.org/stable/c/a73d95b57bf9faebdfed591bcb7ed9292062a84c (opens in a new tab)
- git.kernel.org/stable/c/37bef86e5428d59f70a4da82b80f9a8f252fecbe (opens in a new tab)
- git.kernel.org/stable/c/4c9af67f99aa3e51b522c54968ab3ac8272be41c (opens in a new tab)
- git.kernel.org/stable/c/0509b762bc5e8ea7b8391130730c6d8502fc6e69 (opens in a new tab)
- git.kernel.org/stable/c/a0671125d4f55e1e98d9bde8a0b671941987e208 (opens in a new tab)