OpenSSL CMS and Mitigation CVE-2026-63072
CVE-2026-63072 is a High severity (CVSS 7.5) vulnerability in OpenSSL that was publicly disclosed on August 25, 2026 . It affects OpenSSL's CMS (Cryptographic Message Syntax) decryption functionality and can lead to a heap corruption and denial of service (DoS) condition. Summary Product: OpenSSL CVE: CVE-2026-63072 Severity: High (CVSS v3.1: 7.5) Weakness: CWE-787 (Out-of-Bounds Write) Impact: Denial of Service (process crash / heap corruption) Attack Vector: Remote, via a crafted CMS message Privileges Required: None User Interaction: None Technical The vulnerability occurs because OpenSSL's CMS decryption code allocates the key-unwrapping buffer based on a reported key size, but the AES-WRAP-PAD unwrap routine can write more data than expected. This results in a deterministic 8-byte out-of-bounds heap write . An attacker can modify a CMS message to switch the key-wrap algorithm OID from a standard AES wrap variant to an AES-WRAP-PAD variant. When the target a...