Monthly
Bleichenbacher oracle in OpenSSL's CMS_decrypt() and PKCS7_decrypt() functions exposes RSA-encrypted message content to unauthenticated remote attackers who can submit adaptive chosen-ciphertext queries against multi-RecipientInfo CMS/PKCS7 structures. Four active OpenSSL branches are affected (3.4.x, 3.5.x, 3.6.x, and 4.0.x), with patches released under the coordinated OpenSSL security advisory on 2026-06-09. No public exploit code and no active exploitation have been identified at time of analysis; SSVC rates this non-automatable with partial technical impact, consistent with the attack's high operational complexity.
Bleichenbacher oracle in OpenSSL's CMS_decrypt() and PKCS7_decrypt() functions exposes RSA-encrypted message content to unauthenticated remote attackers who can submit adaptive chosen-ciphertext queries against multi-RecipientInfo CMS/PKCS7 structures. Four active OpenSSL branches are affected (3.4.x, 3.5.x, 3.6.x, and 4.0.x), with patches released under the coordinated OpenSSL security advisory on 2026-06-09. No public exploit code and no active exploitation have been identified at time of analysis; SSVC rates this non-automatable with partial technical impact, consistent with the attack's high operational complexity.