CVE-2021-40528

A flaw was found in libgcrypt’s ElGamal implementation, where it allows plain text recovery. During the interaction between two cryptographic libraries, a certain combination of the prime defined by the receiver’s public key, the generator defined by the receiver’s public key, and the sender’s ephemeral exponents can lead to a cross-configuration attack against OpenPGP. The highest threat from this vulnerability is to confidentiality.