{"id":"CVE-2026-72442","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-72442","summary":"netfilter: flowtable: fix and simplify IP6IP6 tunnel handling","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable: fix and simplify IP6IP6 tunnel handling\n\nFix nf_flow_ip6_tunnel_proto() to use pskb_may_pull() instead of\nskb_header_pointer() to ensure the outer IPv6 header is in the skb\nheadroom, which is required for subsequent packet processing. Move\nctx->offset update inside the IPPROTO_IPV6 conditional block since it\nshould only be adjusted when an IP6IP6 tunnel is actually detected.\nSimplify the rx path by removing ipv6_skip_exthdr() and checking\nip6h->nexthdr directly, as the flowtable fast path only handles simple\nIP6IP6 encapsulation without extension headers.\nDrop the tunnel encapsulation limit destination option support from the\ntx path to match, since the rx path no longer handles extension headers.\nRemove the encap_limit parameter from nf_flow_offload_ipv6_forward(),\nnf_flow_tunnel_ip6ip6_push() and nf_flow_tunnel_v6_push(), along with\nthe ipv6_tel_txoption struct and related headroom/MTU adjustments.","published":"2026-08-15T05:56:53.941Z","modified":"2026-08-18T03:56:55.882685953Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"7.1.5"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7f8d816a9aa2729d270418f00c9ef5e85bfc1b31"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f4c2d8668d85ed125985da663c824a9c25498257"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72442.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72442"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:55.882685953Z"}}