{"id":"CVE-2026-88823","published":"2026-11-10T19:21:34.847","lastModified":"2026-11-10T22:10:04.727","description":"Issue summary: The AES-GCM-SIV implementation treats a zero-length Additional\nAuthenticated Data (AAD) update as a reset of all the AAD supplied so far,\ninstead of leaving the AAD unchanged. An application that supplies its AAD in\nseveral fragments, one of which is empty, therefore produces or verifies\nmessages whose authentication tag does not cover the AAD supplied before\nthe empty fragment.\n\nImpact summary: Data an application intended to authenticate alongside a\nmessage is silently left unauthenticated. An attacker can forge the AAD of such\na message.\n\nCWE: CWE-325: Missing Cryptographic Step\n\nDescription: An application passing AAD in multiple chunks of which some have\nzero length will have the previous AAD chunks effectively unauthenticated. Also,\non context re-initialisation, the AAD was not reset, which meant that any AAD\naccumulated from the previous context usage were also included in the AAD of the\nnew message.\n\nThe fix makes a zero-length AAD update a no-op and clears any accumulated AAD\nwhenever the context is re-initialised with a key or a nonce.\nA re-initialisation that only changes parameters keeps the AAD.\n\nFIPS impact: no\nThe FIPS modules are not affected, as AES-GCM-SIV is not a FIPS approved\nalgorithm and is implemented only in the default provider, outside the\nOpenSSL FIPS module boundary.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-325"],"vendors":[],"products":[],"references":[{"url":"https://github.com/openssl/openssl/commit/159e1de0c448d7b9f09ad768c8e141def4aa1eb4","tags":[]},{"url":"https://github.com/openssl/openssl/commit/2f5fc833ff9b5bfe00b32f8b5c74f73c5773c682","tags":[]},{"url":"https://github.com/openssl/openssl/commit/6747b1a278816dd7db46438040a70b0b5e5e0a90","tags":[]},{"url":"https://openssl-library.org/news/secadv/20261110.txt","tags":[]}],"exploitRefs":[{"url":"https://github.com/openssl/openssl/commit/159e1de0c448d7b9f09ad768c8e141def4aa1eb4","tags":[]},{"url":"https://github.com/openssl/openssl/commit/2f5fc833ff9b5bfe00b32f8b5c74f73c5773c682","tags":[]},{"url":"https://github.com/openssl/openssl/commit/6747b1a278816dd7db46438040a70b0b5e5e0a90","tags":[]}],"hasPoc":true,"ai":null}