{"schema":"threatline.record/2","record":{"id":"CVE-2026-98123","aliases":[],"summary":"sctp: fix soft lockup from unpadded ASCONF-ACK parameter iteration","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix soft lockup from unpadded ASCONF-ACK parameter iteration\n\nsctp_verify_asconf() walks ASCONF-ACK parameters with\nsctp_walk_params(), which advances by SCTP_PAD4(length), while the\nconsumer sctp_get_asconf_response() iterates the same parameters\nadvancing by the raw length, without padding. A single odd-length\nparameter desynchronises the two walks and makes the consumer\ninterpret attacker-controlled bytes at a misaligned offset.\n\nWhen those bytes yield a length of zero, the while loop over\nasconf_ack_len makes no progress, spinning forever in softirq\ncontext, and the watchdog reports a soft lockup. All reads stay\nwithin the received skb, so the lockup is a pure remote denial of\nservice. A remote peer can trigger it with a crafted ASCONF-ACK on\nan ADD-IP enabled association with an outstanding ASCONF (RFC 5061\nsection 4.1.2 requires the chunk to be authenticated, but the\npredefined empty key id 0 allows the peer to compute the same\nassociation HMAC from publicly exchanged parameters, so the gate\ndoes not help).\n\nThe SCTP_PARAM_ERR_CAUSE case of sctp_verify_asconf() also performs\nno length check, letting a parameter without a complete error\nheader reach the consumer, which reads errhdr.cause past the end of\nthe parameter, an out-of-bounds read.\n\nReject SCTP_PARAM_ERR_CAUSE parameters shorter than\nsizeof(struct sctp_addip_param) + sizeof(struct sctp_errhdr) at the\nverifier, and advance the consumer iterator with the same padding\nrule as the verifier to keep the two walks in lockstep. The verifier\nchange guarantees a complete error header in every ERR_CAUSE\nparameter the consumer can see, so the consumer's asconf_ack_len\ncheck is dropped and it returns err_param->cause directly. The\nconsumer padding fix is still required because odd lengths remain\nvalid for SCTP_PARAM_ERR_CAUSE per RFC 5061.\n\nThe issue was found by ZeroHive, a vulnerability hunting agent at\nTencent Yunding Lab.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98123","source_modified_at":"2026-10-19T09:14:15.281Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"ba54cad229977f4fae6355dbdaf117088414fdd0","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"7d8e7ab6a0665888beee91f7ad77ac805963c4fd","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"5fbc6a778d5fce7628821236972596acb18e1065","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"4548d843e7b29f6d150d8caae4e64015fa226b0c","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"abf59d7f6fff23227256e8199aca5ade45758f8b","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"3be02999ab9131a4b96eb1eda4ca48b1cea80f03","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"7ba84e2971d208a2d6413a334ec28a8a32cdce0f","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"2cb0b0b1ed69430bf73740377ea0a1c44c50db63","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98123","source_modified_at":"2026-10-19T09:14:15.281Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","status":"unaffected","versionType":"semver"},{"version":"5.10.271","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.222","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.189","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.7","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98123","source_modified_at":"2026-10-19T09:14:15.281Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7d8e7ab6a0665888beee91f7ad77ac805963c4fd","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98123","source_modified_at":"2026-10-19T09:14:15.281Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"5fbc6a778d5fce7628821236972596acb18e1065","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98123","source_modified_at":"2026-10-19T09:14:15.281Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"4548d843e7b29f6d150d8caae4e64015fa226b0c","basis":"first unaffected version stated in the CVE record"},{"source":"CVE 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record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00095,"percentile":0.0061,"score_date":"2026-10-23"},"published_at":"2026-09-25T10:36:05.993Z","modified_at":"2026-10-19T09:14:15.281Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98123","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:14:15.281Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98123","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/ba54cad229977f4fae6355dbdaf117088414fdd0"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7d8e7ab6a0665888beee91f7ad77ac805963c4fd"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/5fbc6a778d5fce7628821236972596acb18e1065"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/4548d843e7b29f6d150d8caae4e64015fa226b0c"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/abf59d7f6fff23227256e8199aca5ade45758f8b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/3be02999ab9131a4b96eb1eda4ca48b1cea80f03"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7ba84e2971d208a2d6413a334ec28a8a32cdce0f"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/2cb0b0b1ed69430bf73740377ea0a1c44c50db63"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:14:15.281Z","content_hash":"cac5d1a48c9154f44a0486ea177aec75d1fa2b280974201582fbe82cca007247"}}