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.

PUBLISHED Reserved 2026-03-09 | Published 2026-04-22 | Updated 2026-05-11 | Assigner Linux

Product status

References

git.kernel.org/...c/435b576cd2faa75154777868f8cbb73bf71644d3

git.kernel.org/...c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474

git.kernel.org/...c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5

git.kernel.org/...c/fcec5ce2d73a41668b24e3f18c803541602a59f6

git.kernel.org/...c/675c913b940488a84effdeeac5a1cfb657b59804

git.kernel.org/...c/c6cb41eaae875501eaaa487b8db6539feb092292

git.kernel.org/...c/45c33e79ae705b7af97e3117672b6cd258dd0b1b

git.kernel.org/...c/8f15b5071b4548b0aafc03b366eb45c9c6566704

cve.org (CVE-2026-31495)

nvd.nist.gov (CVE-2026-31495)

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