{"api_version":"1","generated_at":"2026-10-24T20:39:52+00:00","cve":"CVE-2026-98531","urls":{"html":"https://cve.report/CVE-2026-98531","api":"https://cve.report/api/cve/CVE-2026-98531.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98531","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98531"},"summary":{"title":"ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: enforce exact attribute length for SEG6_ATTR_DST\n\nIn seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and\n.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the\nmaximum payload length and permits shorter payloads (e.g., 0 bytes).\nWhen seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via\nkmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute\ntriggers a 16-byte out-of-bounds read past skb->tail into uninitialized\nskb->head memory, which is stored in sdata->tun_src and leaked back to\nuserspace via SEG6_CMD_GET_TUNSRC.\n\nSwitch SEG6_ATTR_DST in seg6_genl_policy to\nNLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink\nvalidation rejects any attribute whose length is not exactly\nsizeof(struct in6_addr) with -ERANGE.\n\nTested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC\nGeneric Netlink message with a 0-byte SEG6_ATTR_DST attribute followed\nby SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC\nsucceeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of\nuninitialized kernel heap memory (tun_src =\n836a61ecc4d25a1042a8d60411cfb378); with this patch applied,\nSEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with\n-ERANGE (-34) and tun_src remains zeroed.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:04","updated_at":"2026-10-18 16:17:04"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670","name":"https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199","name":"https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70","name":"https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e","name":"https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418","name":"https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9","name":"https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd","name":"https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741","name":"https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98531","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98531","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 050a0aa3c80907b8c60a396b7e04d48d8b1a9e70 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 209eefebee54c4a5f01d68b61e8ac9881eca2de9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa e3ac68c1cdc2535d127b2bfd50c263d16c8e4199 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 66bf65fa109326e4c4ddeb0b94093379f72838fd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 195813bb7324c338eaba0aaa02b18681ee65b670 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 6fcfc362344edea745a69f3a705de50b731f3418 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 915d7e5e5930b4f01d0971d93b9b25ed17d221aa 2d959c75c27f90e9ec489d18ce5ee6b852ad4741 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.10","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.10 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.271 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.222 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.189 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.158 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.112 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.55 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.9 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv6/seg6.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"050a0aa3c80907b8c60a396b7e04d48d8b1a9e70","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"209eefebee54c4a5f01d68b61e8ac9881eca2de9","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"e3ac68c1cdc2535d127b2bfd50c263d16c8e4199","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"66bf65fa109326e4c4ddeb0b94093379f72838fd","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"195813bb7324c338eaba0aaa02b18681ee65b670","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"6fcfc362344edea745a69f3a705de50b731f3418","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"},{"lessThan":"2d959c75c27f90e9ec489d18ce5ee6b852ad4741","status":"affected","version":"915d7e5e5930b4f01d0971d93b9b25ed17d221aa","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv6/seg6.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.10"},{"lessThan":"4.10","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.271","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.222","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.189","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.158","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.112","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.55","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.271","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.222","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.189","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.158","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.112","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.55","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.9","versionStartIncluding":"4.10","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"4.10","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: enforce exact attribute length for SEG6_ATTR_DST\n\nIn seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and\n.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the\nmaximum payload length and permits shorter payloads (e.g., 0 bytes).\nWhen seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via\nkmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute\ntriggers a 16-byte out-of-bounds read past skb->tail into uninitialized\nskb->head memory, which is stored in sdata->tun_src and leaked back to\nuserspace via SEG6_CMD_GET_TUNSRC.\n\nSwitch SEG6_ATTR_DST in seg6_genl_policy to\nNLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink\nvalidation rejects any attribute whose length is not exactly\nsizeof(struct in6_addr) with -ERANGE.\n\nTested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC\nGeneric Netlink message with a 0-byte SEG6_ATTR_DST attribute followed\nby SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC\nsucceeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of\nuninitialized kernel heap memory (tun_src =\n836a61ecc4d25a1042a8d60411cfb378); with this patch applied,\nSEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with\n-ERANGE (-34) and tun_src remains zeroed."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:21:14.351Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/050a0aa3c80907b8c60a396b7e04d48d8b1a9e70"},{"url":"https://git.kernel.org/stable/c/209eefebee54c4a5f01d68b61e8ac9881eca2de9"},{"url":"https://git.kernel.org/stable/c/e3ac68c1cdc2535d127b2bfd50c263d16c8e4199"},{"url":"https://git.kernel.org/stable/c/66bf65fa109326e4c4ddeb0b94093379f72838fd"},{"url":"https://git.kernel.org/stable/c/195813bb7324c338eaba0aaa02b18681ee65b670"},{"url":"https://git.kernel.org/stable/c/6fcfc362344edea745a69f3a705de50b731f3418"},{"url":"https://git.kernel.org/stable/c/94214cf0a08dd2c5f37aeeea46078d9dfe8e4a0e"},{"url":"https://git.kernel.org/stable/c/2d959c75c27f90e9ec489d18ce5ee6b852ad4741"}],"title":"ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98531","datePublished":"2026-10-18T15:17:49.632Z","dateReserved":"2026-09-25T10:25:14.355Z","dateUpdated":"2026-10-19T09:21:14.351Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:04","lastModifiedDate":"2026-10-18 16:17:04","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98531","Ordinal":"1","Title":"ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST","CVE":"CVE-2026-98531","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98531","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: sr: enforce exact attribute length for SEG6_ATTR_DST\n\nIn seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and\n.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the\nmaximum payload length and permits shorter payloads (e.g., 0 bytes).\nWhen seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via\nkmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute\ntriggers a 16-byte out-of-bounds read past skb->tail into uninitialized\nskb->head memory, which is stored in sdata->tun_src and leaked back to\nuserspace via SEG6_CMD_GET_TUNSRC.\n\nSwitch SEG6_ATTR_DST in seg6_genl_policy to\nNLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink\nvalidation rejects any attribute whose length is not exactly\nsizeof(struct in6_addr) with -ERANGE.\n\nTested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC\nGeneric Netlink message with a 0-byte SEG6_ATTR_DST attribute followed\nby SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC\nsucceeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of\nuninitialized kernel heap memory (tun_src =\n836a61ecc4d25a1042a8d60411cfb378); with this patch applied,\nSEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with\n-ERANGE (-34) and tun_src remains zeroed.","Type":"Description","Title":"ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST"}]}}}