CVE-2018-6829: Gnupg Libgcrypt

High severity, CVSS 7.5. EPSS: 1.8% chance of exploitation in the next 30 days.

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.

Affected products

• Gnupg Libgcrypt: up to and including 1.8.2

Published 2018-02-07. Last modified 2026-06-17.