Description
The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libgcrypt20 | 1.8.7-6 | — |
| Debian 13 | libgcrypt20 | 1.8.7-6 | — |
| Debian 12 | libgcrypt20 | 1.8.7-6 | — |
| Debian 9 | libgcrypt20 | 1.7.6-2+deb9u4 | DLA-2691-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | libgcrypt20 | 1.8.7-5ubuntu2 | — |
| Ubuntu 20.04 LTS | libgcrypt20 | 1.8.5-5ubuntu1.1 | USN-5080-1 |
| Ubuntu 18.04 LTS | libgcrypt20 | 1.8.1-4ubuntu1.3 | USN-5080-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | libgcrypt20 | 1.8.5-5ubuntu1.fips.1.1 | — |
| Ubuntu Pro FIPS 18.04 LTS | libgcrypt20 | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | libgcrypt20 | 1.8.5-5ubuntu1.fips.1.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | libgcrypt20 | 1.8.1-4ubuntu1.fips.3 | — |
| Ubuntu Pro 16.04 LTS | libgcrypt20 | 1.6.5-2ubuntu0.6+esm1 | USN-5080-2 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | libgcrypt +1 | 1.8.5-7.el8_6 | RHSA-2022:5311 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | libgcrypt +1 | 1.8.5-7.el8_6 | ALSA-2022:5311 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libgcrypt | 1.8.5-7.el8_6 | RLSA-2022:5311 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libgcrypt | 1.10.1-1.1 | openSUSE-SU-2024:12540-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.13 | libgcrypt | 1.8.8-r1 | — |
| Alpine v3.12 | libgcrypt | 1.8.8-r1 | — |
| Alpine v3.11 | libgcrypt | 1.8.8-r1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | libgcrypt +1 | 1.8.5-7.el8_6 | ELSA-2022-9564, ELSA-2022-5311 |
Advisories 11
- ALSA-2022:5311 Moderate: libgcrypt security update AlmaLinux Security Advisories · Oct 29, 2026
- USN-5080-2 libgcrypt20 vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-5080-1 libgcrypt20 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-2691-1 libgcrypt20 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2022:5311 Moderate: libgcrypt security update Rocky Linux Security Advisories · Feb 4, 2026
- RHSA-2022:5311 Red Hat Security Advisory: libgcrypt security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- openSUSE-SU-2024:12540-1 libgcrypt-devel-1.10.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- WID-SEC-2023-0137 Oracle Communications: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 21, 2024
- WID-SEC-2023-1812 Oracle Communications: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jul 20, 2023
- ELSA-2022-9564 Important: libgcrypt security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 7, 2022
- ELSA-2022-5311 Moderate: libgcrypt security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 1, 2022
References
- https://eprint.iacr.org/2021/923
- https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1
- https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2
- https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=3462280f2e23e16adf3ed5176e0f2413d8861320
- GLSA-202210-13 vendor-advisory