CVE-2026-31496: Linux kernel · netfilter: nf_conntrack_expect: skip expectations in other netns via proc
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in dcfcd95b3ae7683e8ae55c92284b3430ce614bc7 : update Linux kernel when convenient.
Data as of 5 Nov 2026, 22:19 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- 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
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-05.
- Patch
- Available – fixed in dcfcd95b3ae7683e8ae55c92284b3430ce614bc7, 2028405ea6987b4448784e439413202cfe19f43f, 168145c87444619e3e649322bbe7719ecd00d411 +3
Exploitation evidence
Disclosed: evidence found.
CVE published 22 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 5 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
A fix for this vulnerability has been implemented in the Linux kernel. Users should update to a kernel version that includes the fix identified by the provided commit hashes. Since this is a kernel-level fix, applying the updated kernel version is the recommended remediation.
Description
A vulnerability in the Linux kernel's netfilter subsystem (nf_conntrack_expect) allowed expectations from other network namespaces (netns) to be processed via the proc interface. This issue was resolved by ensuring that expectations not residing in the current netns are skipped, preventing cross-netns information leakage or interference.
References
- git.kernel.org/stable/c/2028405ea6987b4448784e439413202cfe19f43f (opens in a new tab)
- git.kernel.org/stable/c/168145c87444619e3e649322bbe7719ecd00d411 (opens in a new tab)
- git.kernel.org/stable/c/dcfcd95b3ae7683e8ae55c92284b3430ce614bc7 (opens in a new tab)
- git.kernel.org/stable/c/9ca8c7452493d915f9bbf2f39331e6c583d07a23 (opens in a new tab)
- git.kernel.org/stable/c/3265ad619987cb551edaf797ed056d80ac450225 (opens in a new tab)
- git.kernel.org/stable/c/3db5647984de03d9cae0dcddb509b058351f0ee4 (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)