gcrymdblockwrite in cipher/hash-common.c in Libgcrypt version 1.9.0 has a heap-based buffer overflow when the digest final function sets a large count value. It is recommended to upgrade to 1.9.1 or later.

GnuPG Libgcrypt could allow a remote attacker to obtain sensitive information, caused by improper handling of ElGamal encryption. By using side-channel attack techniques against mpipowm, and the window size, an attacker could exploit this vulnerability to obtain sensitive information, and use this information to launch further attacks against the affected system.