CVE-2026-63573 Bleichenbacher padding oracle in CMS RSA PKCS#1 v1.5 key-transport unwrap

Observable discrepancy in the CMS RSA PKCS1 v1.5 key-transport unwrap KeyTransRecipientInformation.UnwrapKey in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker who holds a captured CMS EnvelopedData message, and who can submit many modified messages to an...