CVE-2026-23351: Linux kernel · Use After Free
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in c12d570d71920903a1a0468b7d13b085203d0c93 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% 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 c12d570d71920903a1a0468b7d13b085203d0c93, c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a, aff13667708dfa0dce136b8efd81baa9fa6ef261 +5
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 25 Mar 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
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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
A fix is available and has been applied in multiple Linux kernel commits as listed in the established facts. Users should update to a Linux kernel version including these fixes to remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-23351 is a use-after-free vulnerability in the Linux kernel's netfilter nft_set_pipapo implementation. The flaw arises because garbage collection (GC) of expired elements runs in a non-preemptible context, causing potential soft lockups and RCU stalls, leading to local denial of service. The fix involves splitting GC into unlink and reclaim phases to prevent access to freed elements during packet processing and userspace dumps.
References
- git.kernel.org/stable/c/65ca51b9fb85477ab92a04295aed34b38f7c062e (opens in a new tab)
- git.kernel.org/stable/c/c0f1f85097ac2b6e7d750fe4d05807985cd3fd3a (opens in a new tab)
- git.kernel.org/stable/c/16f3595c0441d87dfa005c47d8f95be213afaa9e (opens in a new tab)
- git.kernel.org/stable/c/7864c667aed01a58b87ca518a631322cd0ac34c0 (opens in a new tab)
- git.kernel.org/stable/c/c12d570d71920903a1a0468b7d13b085203d0c93 (opens in a new tab)
- git.kernel.org/stable/c/500a50a301ce962b019ab95053ac70264fec2c21 (opens in a new tab)
- git.kernel.org/stable/c/aff13667708dfa0dce136b8efd81baa9fa6ef261 (opens in a new tab)
- git.kernel.org/stable/c/9df95785d3d8302f7c066050117b04cd3c2048c2 (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)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)