CVE-2018-6829
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.78%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 1.78% probability · 78th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-327
- Affected
- gnupg/libgcrypt
- Source
- cve@mitre.org
EPSS 1.8% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/weikengchen/attack-on-libgcrypt-elgamalThird Party Advisory
- https://github.com/weikengchen/attack-on-libgcrypt-elgamal/wikiExploit, Third Party Advisory
- https://lists.gnupg.org/pipermail/gcrypt-devel/2018-February/004394.htmlIssue Tracking, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2020.html
- https://github.com/weikengchen/attack-on-libgcrypt-elgamalThird Party Advisory
- https://github.com/weikengchen/attack-on-libgcrypt-elgamal/wikiExploit, Third Party Advisory
- https://lists.gnupg.org/pipermail/gcrypt-devel/2018-February/004394.htmlIssue Tracking, Third Party Advisory
- https://www.oracle.com/security-alerts/cpujan2020.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.