{"id":"CVE-2026-75806","published":"2026-09-29T16:17:11.217","lastModified":"2026-09-29T21:27:41.130","description":"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.","cvssScore":5.3,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","cwes":["CWE-1284"],"vendors":[],"products":[],"references":[{"url":"https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d","tags":[]},{"url":"https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972","tags":[]},{"url":"https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d","tags":[]},{"url":"https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d","tags":[]},{"url":"https://openssl-library.org/news/secadv/20260929.txt","tags":[]}],"exploitRefs":[{"url":"https://github.com/openssl/openssl/commit/04728a289a823e68137f88da016cb9ede307217d","tags":[]},{"url":"https://github.com/openssl/openssl/commit/050b275cd671a6eed1d6457642d41a5a77aab972","tags":[]},{"url":"https://github.com/openssl/openssl/commit/3a4589d015a9049d47b66f186cf50a8711343a1d","tags":[]},{"url":"https://github.com/openssl/openssl/commit/5af82fefbaf2b5fec2fc0e1d87f112844902f01d","tags":[]}],"hasPoc":true,"ai":null}