OpenSSL AES-OCB IV Ignored on EVP_Cipher() Path
CVE-2026-45445 is a flaw in OpenSSL's AES-OCB handling when applications use the public one-shot EVP_Cipher() API instead of the documented streaming interface. In affected versions, the OCB provider's one-shot handler fails to flush the application-supplied IV into the OCB context before processing data, so the supplied IV is silently discarded. As a result, each EVP_Cipher() call on an AES-OCB context runs with the all-zero key-derived offset state left by cipher initialization rather than the caller's intended nonce/IV. This causes every message encrypted under the same key to use the same effective nonce. Additionally, if EVP_EncryptFinal_ex() is then used to obtain the authentication tag, deferred IV setup occurs at finalization time and clears the running checksum that should reflect the plaintext, causing the resulting tag to depend only on the key and IV rather than the plaintext or ciphertext. The issue affects OpenSSL 4.0.0 before 4.0.1, 3.6.0 before 3.6.3, 3.5.0 before 3.5.7, 3.4.0 before 3.4.6, and 3.0.0 before 3.0.21. OpenSSL SSL/TLS is not affected, and applications using the documented EVP_CipherUpdate()/EVP_CipherFinal_ex() streaming AEAD API are not vulnerable. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected because AES-OCB is outside the FIPS module boundary.
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An OpenSSL vulnerability addressed in Alpine Linux 3.22.5 and 3.23.5 as part of the June 9, 2026 OpenSSL advisory.
An OpenSSL vulnerability addressed in Alpine Linux 3.24.1 as part of the June 9, 2026 advisory.
An OpenSSL AES-OCB one-shot interface flaw that ignores the supplied IV, causing nonce reuse and resulting in severe confidentiality loss and possible authentication tag forgery.
A moderate OpenSSL AES-OCB flaw in the EVP_Cipher() one-shot path where the supplied IV is ignored, causing nonce reuse, loss of confidentiality, and possible universal forgery.
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