CVE-2026-52915

netfilter: ip6t_hbh: reject oversized option lists

HIGH
7.1
CVSS Score
Published: June 24, 2026 at 07:14 AM UTC
Updated: October 19, 2026 at 08:18 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.1
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: ip6t_hbh: reject oversized option lists struct ip6t_opts stores at most IP6T_OPTS_OPTSNR option descriptors, but hbh_mt6_check() does not reject larger optsnr values supplied from userspace. Validate optsnr in the rule setup path so only match data that fits the fixed-size opts array can be installed. This follows the existing xtables pattern of rejecting invalid user-provided counts in checkentry() and keeps the packet matching path unchanged. `struct ip6t_opts` has a fixed `opts[IP6T_OPTS_OPTSNR]` array, where `IP6T_OPTS_OPTSNR` is 16, then off-by-one array access is possible: [ 137.924693][ T8692] UBSAN: array-index-out-of-bounds in ../net/ipv6/netfilter/ip6t_hbh.c:110:29 [ 137.926167][ T8692] index 16 is out of range for type '__u16 [16]'

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.6.12.1 ≤ v < 5.10.2585.11 ≤ v < 5.15.2095.16 ≤ v < 6.1.1756.13 ≤ v < 6.18.346.19 ≤ v < 7.0.116.2 ≤ v < 6.6.1426.7 ≤ v < 6.12.921da177e4c3f41524e886b7f1b8a0c1fc7321cac22.6.122.6.12 rc22.6.12 rc32.6.12 rc42.6.12 rc57.17.1 rc17.1 rc27.1 rc37.1 rc4
Vendor states this is fixed in 2d523ba48d4ecc46acfb6aba548292cfcce1ac02 (fixed)
Vendor states this is fixed in 41ec2e242f1702e8370ddfe14d22b7a766021c3e (fixed)
Vendor states this is fixed in 4322dcde6b4173c2d8e8e6118ed290794263bcc8 (fixed)
Vendor states this is fixed in 57b0ac5e1b46f1f0338dff392ef2092e2871b412 (fixed)
Vendor states this is fixed in 588933f1a2ca5ff99274f8c9f25dc3a25d0191c3 (fixed)
Vendor states this is fixed in 6feb43c0995ab3a9c826707eb46541a1696fe4f7 (fixed)
Vendor states this is fixed in 784aadea7a108c9f90985683caa87fb0198c6a39 (fixed)
Vendor states this is fixed in db0250470f023f159094052c0bd5ab026a88ae93 (fixed)
Vendor states this is fixed in 2.6.12 (unaffected)
Vendor states this is fixed in 5.10.258 (unaffected)
Vendor states this is fixed in 5.15.209 (unaffected)
Vendor states this is fixed in 6.1.175 (unaffected)
Vendor states this is fixed in 6.12.92 (unaffected)
Vendor states this is fixed in 6.18.34 (unaffected)
Vendor states this is fixed in 6.6.142 (unaffected)
Vendor states this is fixed in 7.0.11 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-129CWE-125

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