{"id":"CVE-2026-72400","revision":"1621a64a5db04fc6aa308b15b9d3ce3c","records":[{"revision":"1621a64a5db04fc6aa308b15b9d3ce3c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72400","aliases":[],"title":"seg6: validate SRH length before reading fixed fields","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nseg6: validate SRH length before reading fixed fields\n\nseg6_validate_srh() reads fixed SRH fields such as srh->type and\nsrh->hdrlen before checking that the supplied length covers the fixed\nstruct ipv6_sr_hdr fields.\n\nThe BPF SEG6 encap path reaches this with a BPF program-supplied pointer\nand length: bpf_lwt_push_encap() and the SEG6 local BPF END_B6 and\nEND_B6_ENCAP actions call bpf_push_seg6_encap(), which forwards the\nlength to seg6_validate_srh() with no minimum-size guard.  A 2-byte SEG6\nencap header can therefore make the validator read srh->type at offset 2\nbeyond the caller-supplied buffer.\n\nReject lengths shorter than the fixed SRH at the top of\nseg6_validate_srh(), before any field is read.  This fixes the BPF helper\npath and keeps the common validator robust.","state":0,"publishedAt":"2026-08-15T05:56:25.572+00:00","modifiedAt":"2026-10-16T18:55:21.67+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/seg6.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"715eb12e453df752f1b4baaf972c3acff0ab9402\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"7247d05c987c3eec4bb7c2306dbd77ecdf3b7c73\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"071f1a38d7ddbadee29c09b9e3ee0ff3a61e6a0e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"804bb969f194c93497ba632b98343794c6367fdc\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"0fc7069d39239978130c37ebceaec85c8948d3f1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"8dba7a94a269b88e500aafc25ad567ef6a423698\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"c9961336aa5ff83092f23e33ee86666a9dbd1b2a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fe94cc290f535709d3c5ebd1e472dfd0aec7ee79\",\n                            \"lessThan\": \"a75d99f46bf21b45965ce39c5cfb3b8bb5ffb1aa\",\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/seg6.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.18\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.18\",\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/715eb12e453df752f1b4baaf972c3acff0ab9402","https://git.kernel.org/stable/c/7247d05c987c3eec4bb7c2306dbd77ecdf3b7c73","https://git.kernel.org/stable/c/071f1a38d7ddbadee29c09b9e3ee0ff3a61e6a0e","https://git.kernel.org/stable/c/804bb969f194c93497ba632b98343794c6367fdc","https://git.kernel.org/stable/c/0fc7069d39239978130c37ebceaec85c8948d3f1","https://git.kernel.org/stable/c/8dba7a94a269b88e500aafc25ad567ef6a423698","https://git.kernel.org/stable/c/c9961336aa5ff83092f23e33ee86666a9dbd1b2a","https://git.kernel.org/stable/c/a75d99f46bf21b45965ce39c5cfb3b8bb5ffb1aa"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72400","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72400","identifiers":["CVE-2026-72400"]},"retained":false,"historicalAffected":[]}],"coverage":[]}