python-gnupg 0.4.3 allows context-dependent attackers to trick gnupg to decrypt other ciphertext than intended. To perform the attack, the passphrase to gnupg must be controlled by the adversary and the ciphertext should be trusted. Related to a "CWE-20: Improper Input Validation" issue affecting the affect functionality component.
mainproc.c in GnuPG before 2.2.8 mishandles the original filename during decryption and verification actions, which allows remote attackers to spoof the output that GnuPG sends on file descriptor 2 to other programs that use the "--status-fd 2" option. For example, the OpenPGP data might represent an original filename that contains line feed characters in conjunction with GOODSIG or VALIDSIG status codes.