AES-OCB Cipher Vulnerability in OpenSSL Products

CVE-2026-45445

What is CVE-2026-45445?

An implementation flaw exists in OpenSSL's AES-OCB cipher where the application-supplied initialization vector (IV) is ignored when using the EVP_Cipher() one-shot interface. This results in key and nonce reuse, leading to potential data exposure and forgery vulnerabilities. The problem stems from the way the cipher state is initialized, which does not leverage the provided IV, thereby compromising the confidentiality of the encrypted messages. Notably, applications utilizing the recommended streaming interface (EVP_CipherUpdate / EVP_CipherFinal_ex) remain unaffected.

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