{"schema":"threatline.record/2","record":{"id":"CVE-2026-75806","aliases":[],"summary":"Unauthenticated and Undersized DTLS 1.2 AEAD Record Causes DoS","details":"Issue summary: An established DTLS 1.2 association using an AEAD cipher suite\ncan be terminated by a single unauthenticated datagram whose encrypted\nfragment is shorter than the mandatory explicit IV and authentication tag\noverhead.\n\nImpact summary: An attacker who can send a datagram that is routed to an\nexisting DTLS 1.2 association can tear that association down without knowing\nany key material. This is a Denial of Service limited to the targeted\nassociation. There is no memory safety or confidentiality impact.\n\nCWE: CWE-1284: Improper Validation of Specified Quantity in Input\n\nDescription: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher\nsuite carries an explicit IV followed by the ciphertext and an authentication\ntag. When decrypting such a record the record layer passed the record length to\nthe cipher implementation before checking that the record was long enough to\ncontain the explicit IV and the tag. For a record shorter than that overhead the\ncipher implementation rejected the impossible length, and the record layer\ntreated this as an internal failure and raised a fatal internal_error alert\ninstead of treating the record as one that failed authentication.\n\nIn TLS 1.2 the same record causes a fatal internal_error alert instead of the\nexpected bad_record_mac alert. Since any undecryptable record already\nterminates a TLS connection, this is a protocol conformance issue rather than\na security issue in TLS.\n\nThe fix validates the record length against the explicit IV and tag length\nbefore any AEAD processing, so that TLS reports bad_record_mac and DTLS\nsilently discards the record.\n\nFIPS impact: no\nThe affected code is outside the FIPS module boundary.","categories":["Libraries & packages"],"product":"OpenSSL","vendor":"OpenSSL","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"OpenSSL","vendor":"OpenSSL","versions":[{"lessThan":"4.0.3","status":"affected","version":"4.0.0","versionType":"semver"},{"lessThan":"3.6.5","status":"affected","version":"3.6.0","versionType":"semver"},{"lessThan":"3.5.9","status":"affected","version":"3.5.0","versionType":"semver"},{"lessThan":"3.4.8","status":"affected","version":"3.4.0","versionType":"semver"},{"lessThan":"3.0.23","status":"affected","version":"3.0.0","versionType":"semver"},{"lessThan":"1.1.1zj","status":"affected","version":"1.1.1","versionType":"custom"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"OpenSSL","ecosystem":null},"version":"4.0.3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"OpenSSL","ecosystem":null},"version":"3.6.5","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"OpenSSL","ecosystem":null},"version":"3.5.9","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"OpenSSL","ecosystem":null},"version":"3.4.8","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"OpenSSL","ecosystem":null},"version":"3.0.23","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","source_modified_at":"2026-09-29T16:53:23.785Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"OpenSSL","ecosystem":null},"version":"1.1.1zj","basis":"first unaffected version stated in the CVE record"}],"cvss":5.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00387,"percentile":0.31587,"score_date":"2026-10-23"},"published_at":"2026-09-29T15:32:21.457Z","modified_at":"2026-09-29T16:53:23.785Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-75806","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-29T16:53:23.785Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-75806","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://openssl-library.org/news/secadv/20260929.txt","tags":["vendor-advisory"]},{"source":"CVE List","url":"https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d","tags":["patch"]},{"source":"CVE List","url":"https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972","tags":["patch"]},{"source":"CVE List","url":"https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d","tags":["patch"]},{"source":"CVE List","url":"https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d","tags":["patch"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CISA ADP","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"partial","assessed_at":"2026-09-29T16:52:47.298458Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-09-29T16:53:23.785Z","content_hash":"226609b8f4766652bc2c107790070e60123b2d02a9116e958445248b1643c398"}}