GnuPG 1.4.x, 2.0.x, and 2.1.x treats a key flags subpacket with all bits cleared (no usage permitted) as if it has all bits set (all usage permitted), which might allow remote attackers to bypass intended cryptographic protection mechanisms by leveraging the subkey.

GnuPG before 1.4.14, and Libgcrypt before 1.5.3 as used in GnuPG 2.0.x and possibly other products, allows local users to obtain private RSA keys via a cache side-channel attack involving the L3 cache, aka Flush+Reload.

The read_block function in g10/import.c in GnuPG 1.4.x before 1.4.13 and 2.0.x through 2.0.19, when importing a key, allows remote attackers to corrupt the public keyring database or cause a denial of service (application crash) via a crafted length field of an OpenPGP packet.

Use-after-free vulnerability in kbx/keybox-blob.c in GPGSM in GnuPG 2.x through 2.0.16 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a certificate with a large number of Subject Alternate Names, which is not properly handled in a realloc operation when importing the certificate or verifying its signature.

GnuPG (gpg) 1.4.8 and 2.0.8 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via crafted duplicate keys that are imported from key servers, which triggers "memory corruption around deduplication of user IDs."

GnuPG 1.4.6 and earlier and GPGME before 1.1.4, when run from the command line, does not visually distinguish signed and unsigned portions of OpenPGP messages with multiple components, which might allow remote attackers to forge the contents of a message without detection.

Heap-based buffer overflow in the ask_outfile_name function in openfile.c for GnuPG (gpg) 1.4 and 2.0, when running interactively, might allow attackers to execute arbitrary code via messages with "C-escape" expansions, which cause the make_printable_string function to return a longer string than expected while constructing a prompt.

Integer overflow in parse_comment in GnuPG (gpg) 1.4.4 allows remote attackers to cause a denial of service (segmentation fault) via a crafted message.

parse-packet.c in GnuPG (gpg) 1.4.3 and 1.9.20, and earlier versions, allows remote attackers to cause a denial of service (gpg crash) and possibly overwrite memory via a message packet with a large length (long user ID string), which could lead to an integer overflow, as demonstrated using the --no-armor option.

The integrity check feature in OpenPGP, when handling a message that was encrypted using cipher feedback (CFB) mode, allows remote attackers to recover part of the plaintext via a chosen-ciphertext attack when the first 2 bytes of a message block are known, and an oracle or other mechanism is available to determine whether an integrity check failed.