{"id":"CVE-2026-72250","revision":"23c5cbf241bc4232bd886645fd0999fa","records":[{"revision":"23c5cbf241bc4232bd886645fd0999fa","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72250","aliases":[],"title":"netfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_reasm: guard mac_header adjustment after IPv6 defrag\n\nnf_ct_frag6_reasm() slides the packet head forward to drop the IPv6\nfragment header and then unconditionally advances skb->mac_header:\n\n\tskb->mac_header += sizeof(struct frag_hdr);\n\nOn the NF_INET_LOCAL_OUT defrag path the skb has no link-layer header\nyet, so skb->mac_header is still the \"not set\" sentinel (u16)~0U. Adding\nsizeof(struct frag_hdr) wraps it to a small value (0xffff + 8 == 7),\nafter which skb_mac_header_was_set() wrongly reports a MAC header is\npresent and skb_mac_header() points into the headroom.\n\nThe reassembler has done this unconditional add since it was introduced;\nit was harmless while mac_header was a bare pointer, but wrong once\nmac_header became a u16 offset whose unset state is the ~0U sentinel\ntested by skb_mac_header_was_set(). The sibling net/ipv6/reassembly.c\ndoes the same relocation and does guard the adjustment; mirror the\nguard here.","state":0,"publishedAt":"2026-08-15T05:54:39.134+00:00","modifiedAt":"2026-10-16T18:55:13.023+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/netfilter/nf_conntrack_reasm.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"6e8cd710ca35c576f5f2e5a396047c9ac61f75e5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"2a95ec21824a8ad81ad660b12231456fc0ac9830\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"bbcdef2061b170af45702ce6b359c02c12acfc94\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"53ef70a315420ed31581d38343684b3bf9a3c76d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"a58230f3a7c4f6c3261786bc1efb72c42e68cd25\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"00bdce2fda7e430d24cfbc96764a1b96deb31f82\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9fb9cbb1082d6b31fb45aa1a14432449a0df6cf1\",\n                            \"lessThan\": \"3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/ipv6/netfilter/nf_conntrack_reasm.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/6e8cd710ca35c576f5f2e5a396047c9ac61f75e5","https://git.kernel.org/stable/c/2a95ec21824a8ad81ad660b12231456fc0ac9830","https://git.kernel.org/stable/c/bbcdef2061b170af45702ce6b359c02c12acfc94","https://git.kernel.org/stable/c/cd0d7bbc027b4d3329712cdcdeb4e5567ffd0d58","https://git.kernel.org/stable/c/53ef70a315420ed31581d38343684b3bf9a3c76d","https://git.kernel.org/stable/c/a58230f3a7c4f6c3261786bc1efb72c42e68cd25","https://git.kernel.org/stable/c/00bdce2fda7e430d24cfbc96764a1b96deb31f82","https://git.kernel.org/stable/c/3b08fed5b7e0d5e3a25d73ef3ba09cd33ade16c9"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72250","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72250","identifiers":["CVE-2026-72250"]},"retained":false,"historicalAffected":[]}],"coverage":[]}