CVEvulnerability

CVE-2026-31495

5.5 MEDIUM Published 2026-04-22 Modified 2026-10-15 Official page ↗
Status
Modified
Published
2026-04-22
Last modified
2026-10-15
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

Affected configurations

• linux linux kernel (>= 2.6.22.1 < 5.10.253) • linux linux kernel (>= 5.11 < 5.15.203) • linux linux kernel (>= 5.16 < 6.1.168) • linux linux kernel (>= 6.2 < 6.6.131) • linux linux kernel (>= 6.7 < 6.12.80) • linux linux kernel (>= 6.13 < 6.18.21) • linux linux kernel (>= 6.19 < 6.19.11) • linux linux kernel 2.6.22 • linux linux kernel 7.0

References