CVE-2026-52915

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfilter: ip6t_hbh: reject oversized option lists<br /> <br /> struct ip6t_opts stores at most IP6T_OPTS_OPTSNR option descriptors,<br /> but hbh_mt6_check() does not reject larger optsnr values supplied from<br /> userspace.<br /> <br /> Validate optsnr in the rule setup path so only match data that fits the<br /> fixed-size opts array can be installed. This follows the existing xtables<br /> pattern of rejecting invalid user-provided counts in checkentry() and<br /> keeps the packet matching path unchanged.<br /> <br /> `struct ip6t_opts` has a fixed `opts[IP6T_OPTS_OPTSNR]` array,<br /> where `IP6T_OPTS_OPTSNR` is 16, then off-by-one array access is possible:<br /> <br /> [ 137.924693][ T8692] UBSAN: array-index-out-of-bounds in ../net/ipv6/netfilter/ip6t_hbh.c:110:29<br /> [ 137.926167][ T8692] index 16 is out of range for type &amp;#39;__u16 [16]&amp;#39;