Integer underflow in wcPKCS7DecryptOri when handling crafted Other Recipient Info, leading to incorrect length handling during decryption.

HMAC zero-length tag forgery in EVPDigestVerifyFinal, where a zero-length tag could be accepted as valid during HMAC verification. In the OpenSSL-compatibility HMAC verify path the supplied signature length was only checked as not exceeding the MAC length, so a zero-length or otherwise truncated tag could pass verification. The fix requires the supplied tag length to exactly equal the MAC length and rejects a zero-length MAC, so a forged short or empty tag is no longer accepted.

PKCS7verify signer confusion allows forged signatures, where the signer associated with a signature is not correctly bound, permitting a forged signature to be accepted.