Description
Interaction between the sks-keyserver code through 1.2.0 of the SKS keyserver network, and GnuPG through 2.2.16, makes it risky to have a GnuPG keyserver configuration line referring to a host on the SKS keyserver network. Retrieving data from this network may cause a persistent denial of service, because of a Certificate Spamming Attack.
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | sks | No fix yet | — |
| Ubuntu 18.04 LTS | gnupg2 | 2.2.4-1ubuntu1.5 | USN-5431-1 |
| Ubuntu 18.04 LTS | sks | No fix yet | — |
| Ubuntu 16.04 LTS | sks | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | gnupg +1 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | gnupg | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | gnupg2 +1 | 2.2.20-2.el8 | RHSA-2020:4490 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | gnupg2 +1 | 2.2.20-2.el8 | ALSA-2020:4490 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | gnupg2 | 2.2.20-2.el8 | RLSA-2020:4490 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | gpg2 | 2.2.5-4.11.1 | SUSE-SU-2019:2006-1 |
| SLES 15 | gpg2 | 2.2.5-4.11.1 | SUSE-SU-2019:2006-1 |
| SLES 12 SP4 | gpg2 | 2.0.24-9.8.1 | SUSE-SU-2019:2480-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP4 | gpg2 | 2.0.24-9.8.1 | SUSE-SU-2019:2480-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | gpg2 | 2.2.5-lp151.6.3.1 | openSUSE-SU-2019:1917-1 |
| openSUSE Leap 15.0 | gpg2 | 2.2.5-lp151.6.3.1 | openSUSE-SU-2019:1917-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | gnupg2 +1 | 2.2.20-2.el8 | ELSA-2020-4490 |
Advisories 9
- ALSA-2020:4490 Moderate: gnupg2 security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2025-0227 IBM QRadar SIEM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 11, 2026
- USN-5431-1 gnupg2 vulnerability Ubuntu Security Notices (USN) · Apr 27, 2026
- RLSA-2020:4490 Moderate: gnupg2 security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2019:2480-1 Security update for gpg2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:2006-1 Security update for gpg2 SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2020:4490 Red Hat Security Advisory: gnupg2 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jan 14, 2026
- openSUSE-SU-2019:1917-1 Security update for gpg2 SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2020-4490 Moderate: gnupg2 security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
References
- https://gist.github.com/rjhansen/67ab921ffb4084c865b3618d6955275f
- https://lists.gnupg.org/pipermail/gnupg-announce/2019q3/000439.html
- https://twitter.com/lambdafu/status/1147162583969009664
- FEDORA-2019-2f259a6c0a vendor-advisory
- FEDORA-2019-28a3675529 vendor-advisory
- openSUSE-SU-2019:1917 vendor-advisory
- https://support.f5.com/csp/article/K08654551
- https://support.f5.com/csp/article/K08654551?utm_source=f5support&%3Butm_medium=RSS
- [mina-dev] 20210225 [jira] [Created] (FTPSERVER-500) Security vulnerability in common/lib/log4j-1.2.17.jar mailing-list
- [bookkeeper-issues] 20210628 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8 mailing-list
- [bookkeeper-issues] 20210629 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8 mailing-list