CVE-2026-75806

CVE CVE-2026-75806EUVD EUVD-2026-89011Published 2026-09-29T15:32:21.000ZLast changed 2026-09-29T16:53:23.000ZCVSS 5.3

What the advisory describes

Issue summary: An established DTLS 1.2 association using an AEAD cipher suite can be terminated by a single unauthenticated datagram whose encrypted fragment is shorter than the mandatory explicit IV and authentication tag overhead. Impact summary: An attacker who can send a datagram that is routed to an existing DTLS 1.2 association can tear that association down without knowing any key material. This is a Denial of Service limited to the targeted association. There is no memory safety or confidentiality impact. CWE: CWE-1284: Improper Validation of Specified Quantity in Input Description: In TLS 1.2 and DTLS 1.2 every record protected by an AEAD cipher suite carries an explicit IV followed by the ciphertext and an authentication tag. When decrypting such a record the record layer passed the record length to the cipher implementation before checking that the record was long enough to contain the explicit IV and the tag. For a record shorter than that overhead the cipher implementation rejected the impossible length, and the record layer treated this as an internal failure and raised a fatal internal_error alert instead of treating the record as one that failed authentication. In TLS 1.2 the same record causes a fatal internal_error alert instead of the expected bad_record_mac alert. Since any undecryptable record already terminates a TLS connection, this is a protocol conformance issue rather than a security issue in TLS. The fix validates the record length against the explicit IV and tag length before any AEAD processing, so that TLS reports bad_record_mac and DTLS silently discards the record. FIPS impact: no The affected code is outside the FIPS module boundary.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• OpenSSL — OpenSSL 3.5.0 <3.5.9; 3.4.0 <3.4.8; 4.0.0 <4.0.3; 3.0.0 <3.0.23; 3.6.0 <3.6.5; 1.1.1 <1.1.1zj

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• OpenSSL — OpenSSL

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