CVE-2026-31495
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: use netlink policy range checks Replace manual range and mask validations with netlink policy annotations in ctnetlink code paths, so that the netlink core rejects invalid values early and can generate extack errors. - CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at policy level, removing the manual >= TCP_CONNTRACK_MAX check. - CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE (14). The normal TCP option parsing path already clamps to this value, but the ctnetlink path accepted 0-255, causing undefined behavior when used as a u32 shift count. - CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with CTA_FILTER_F_ALL, removing the manual mask checks. - CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding a new mask define grouping all valid expect flags. Extracted from a broader nf-next patch by Florian Westphal, scoped to ctnetlink for the fixes tree.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.170-1 |
| debian | forky | fixed | 6.19.11-1 |
| debian | sid | fixed | 6.19.11-1 |
| debian | trixie | fixed | 6.12.85-1 |
| debian | bullseye | fixed | 6.1.170-1~deb11u1 |
| linux-kernel | affected | 5.10.253 | |
| linux-kernel | 2.6.22 | affected | |
| linux-kernel | 7.0 | affected | |
References
- https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474
- https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3
- https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b
- https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5
- https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804
- https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704
- https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292
- https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6
- https://www.suse.com/security/cve/CVE-2026-31495.html
- https://security-tracker.debian.org/tracker/CVE-2026-31495
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.