The key validation code in GnuPG before 1.2.2 does not properly determine the validity of keys with multiple user IDs and assigns the greatest validity of the most valid user ID, which prevents GnuPG from warning the encrypting user when a user ID does not have a trusted path.

A "stack overwrite" vulnerability in GnuPG (gpg) 1.x before 1.4.6, 2.x before 2.0.2, and 1.9.0 through 1.9.95 allows attackers to execute arbitrary code via crafted OpenPGP packets that cause GnuPG to dereference a function pointer from deallocated stack memory.

Format string vulnerability in Gnu Privacy Guard (aka GnuPG or gpg) 1.05 and earlier can allow an attacker to gain privileges via format strings in the original filename that is stored in an encrypted file.

GnuPG (gpg) 1.0.3 does not properly check all signatures of a file containing multiple documents, which allows an attacker to modify contents of all documents but the first without detection.

Format string vulnerability in gpgkeyshkp (experimental HKP interface) for the GnuPG (gpg) client 1.2.3 and earlier, and 1.3.3 and earlier, allows remote attackers or a malicious keyserver to cause a denial of service (crash) and possibly execute arbitrary code during key retrieval.

gpg (aka GnuPG) 1.0.4 and other versions imports both public and private keys from public key servers without notifying the user about the private keys, which could allow an attacker to break the web of trust.

GnuPG (GPG) 1.0.2, and other versions up to 1.2.3, creates ElGamal type 20 (sign+encrypt) keys using the same key component for encryption as for signing, which allows attackers to determine the private key from a signature.

gpg in GnuPG before 1.4.2.2 does not properly verify non-detached signatures, which allows attackers to inject unsigned data via a data packet that is not associated with a control packet, which causes the check for concatenated signatures to report that the signature is valid, a different vulnerability than CVE-2006-0455.

gpgv in GnuPG before 1.4.2.1, when using unattended signature verification, returns a 0 exit code in certain cases even when the detached signature file does not carry a signature, which could cause programs that use gpgv to assume that the signature verification has succeeded. Note: this also occurs when running the equivalent command "gpg --verify".

gpg (aka GnuPG) 1.0.4 and other versions does not properly verify detached signatures, which allows attackers to modify the contents of a file without detection.