# CVE-2026-31496: netfilter: nf_conntrack_expect: skip expectations in other netns via proc

Status: published. Published: 2026-04-22. Updated: 2026-11-05.

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_expect: skip expectations in other netns via proc

Skip expectations that do not reside in this netns.

Similar to e77e6ff502ea ("netfilter: conntrack: do not dump other netns's
conntrack entries via proc").

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 9b03f38d0487f3908696242286d934c9b38f9d2a; < 2028405ea6987b4448784e439413202cfe19f43f (affected, git); ≥ 9b03f38d0487f3908696242286d934c9b38f9d2a; < 168145c87444619e3e649322bbe7719ecd00d411 (affected, git); ≥ 9b03f38d0487f3908696242286d934c9b38f9d2a; < dcfcd95b3ae7683e8ae55c92284b3430ce614bc7 (affected, git); ≥ 9b03f38d0487f3908696242286d934c9b38f9d2a; < 9ca8c7452493d915f9bbf2f39331e6c583d07a23 (affected, git); ≥ 9b03f38d0487f3908696242286d934c9b38f9d2a; < 3265ad619987cb551edaf797ed056d80ac450225 (affected, git); ≥ 9b03f38d0487f3908696242286d934c9b38f9d2a; < 3db5647984de03d9cae0dcddb509b058351f0ee4 (affected, git). Source: CNA: Linux
- Linux / Linux: 2.6.28 (affected); ≥ 0; < 2.6.28 (unaffected, semver); ≥ 6.1.168; ≤ 6.1.* (unaffected, semver); ≥ 6.6.131; ≤ 6.6.* (unaffected, semver); ≥ 6.12.80; ≤ 6.12.* (unaffected, semver); ≥ 6.18.21; ≤ 6.18.* (unaffected, semver); ≥ 6.19.11; ≤ 6.19.* (unaffected, semver); ≥ 7.0; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP: ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.6; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.5; < * (affected, custom). Source: ADP: siemens-SADP
- Siemens / SIPLUS S7-1500 CPU 1518-4 PN/DP MFP: ≥ V3.1.7; < * (affected, custom). Source: ADP: siemens-SADP

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-05; percentile 2.24%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/2028405ea6987b4448784e439413202cfe19f43f (CNA: Linux)

- https://git.kernel.org/stable/c/168145c87444619e3e649322bbe7719ecd00d411 (CNA: Linux)

- https://git.kernel.org/stable/c/dcfcd95b3ae7683e8ae55c92284b3430ce614bc7 (CNA: Linux)

- https://git.kernel.org/stable/c/9ca8c7452493d915f9bbf2f39331e6c583d07a23 (CNA: Linux)

- https://git.kernel.org/stable/c/3265ad619987cb551edaf797ed056d80ac450225 (CNA: Linux)

- https://git.kernel.org/stable/c/3db5647984de03d9cae0dcddb509b058351f0ee4 (CNA: Linux)

- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (ADP: siemens-SADP)

- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (ADP: siemens-SADP)

- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (ADP: siemens-SADP)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-31496; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-31496; retrieved 2026-11-05; source updated Not reported

Revision: 500a8f93913c39d829bc3849c33a323dc6fc2a4c7785ef6f08c7434375e64200

Canonical: https://y2.dev/cve/CVE-2026-31496

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