GnuPG 2.2.4 and 2.2.5 does not enforce a configuration in which key certification requires an offline master Certify key, which results in apparently valid certifications that occurred only with access to a signing subkey.

cipher/elgamal.c in Libgcrypt through 1.8.2, when used to encrypt messages directly, improperly encodes plaintexts, which allows attackers to obtain sensitive information by reading ciphertext data (i.e., it does not have semantic security in face of a ciphertext-only attack). The Decisional Diffie-Hellman (DDH) assumption does not hold for Libgcrypt's ElGamal implementation.

Libgcrypt before 1.8.1 does not properly consider Curve25519 side-channel attacks, which makes it easier for attackers to discover a secret key, related to cipher/ecc.c and mpi/ec.c.

In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key. 1.7.7 makes a cipher/ecc-eddsa.c change to store this session key in secure memory, to ensure that constant-time point operations are used in the MPI library.

The mixing functions in the random number generator in Libgcrypt before 1.5.6, 1.6.x before 1.6.6, and 1.7.x before 1.7.3 and GnuPG before 1.4.21 make it easier for attackers to obtain the values of 160 bits by leveraging knowledge of the previous 4640 bits.

ber-decoder.c in Libksba before 1.3.3 does not properly handle decoder stack overflows, which allows remote attackers to cause a denial of service (abort) via crafted BER data.

Libksba before 1.3.4 allows remote attackers to cause a denial of service (out-of-bounds read and crash) via unspecified vectors, related to the "returned length of the object from _ksba_ber_parse_tl."

Multiple integer overflows in ber-decoder.c in Libksba before 1.3.3 allow remote attackers to cause a denial of service (crash) via crafted BER data, which leads to a buffer overflow.

ber-decoder.c in Libksba before 1.3.3 uses an incorrect integer data type, which allows remote attackers to cause a denial of service (crash) via crafted BER data, which leads to a buffer overflow.

The append_utf8_value function in the DN decoder (dn.c) in Libksba before 1.3.3 allows remote attackers to cause a denial of service (out-of-bounds read) by clearing the high bit of the byte after invalid utf-8 encoded data.