CVE-2026-52915
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public 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]'
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-129
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2d523ba48d4ecc46acfb6aba548292cfcce1ac02Patch
- https://git.kernel.org/stable/c/41ec2e242f1702e8370ddfe14d22b7a766021c3ePatch
- https://git.kernel.org/stable/c/4322dcde6b4173c2d8e8e6118ed290794263bcc8Patch
- https://git.kernel.org/stable/c/57b0ac5e1b46f1f0338dff392ef2092e2871b412Patch
- https://git.kernel.org/stable/c/588933f1a2ca5ff99274f8c9f25dc3a25d0191c3Patch
- https://git.kernel.org/stable/c/6feb43c0995ab3a9c826707eb46541a1696fe4f7Patch
- https://git.kernel.org/stable/c/784aadea7a108c9f90985683caa87fb0198c6a39Patch
- https://git.kernel.org/stable/c/db0250470f023f159094052c0bd5ab026a88ae93Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.