Description
In GnuPG before 2.5.5, if a user chooses to import a certificate with certain crafted subkey data that lacks a valid backsig or that has incorrect usage flags, the user loses the ability to verify signatures made from certain other signing keys, aka a "verification DoS."
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| GnuPG | GnuPG | < 2.5.5 | 2.5.5 |
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 | gnupg2 | 2.2.46-5 | — |
| Debian 13 | gnupg2 | 2.2.46-5 | — |
| Debian 12 | gnupg2 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 25.10 | gnupg2 | 2.4.4-2ubuntu23 | — |
| Ubuntu 24.04 LTS | gnupg2 | 2.4.4-2ubuntu17.2 | USN-7412-1 |
| Ubuntu 22.04 LTS | gnupg2 | 2.2.27-3ubuntu2.3 | USN-7412-1 |
| Ubuntu 20.04 LTS | gnupg2 | 2.2.19-3ubuntu2.4 | USN-7412-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | gnupg2 | 2.2.4-1ubuntu1.6+esm1 | — |
| Ubuntu Pro 16.04 LTS | gnupg2 | 2.1.11-6ubuntu2.1+esm2 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | gpg2 | 2.4.4-150600.3.9.1 | SUSE-SU-2025:02259-1 |
| SLES 15 SP6 | gpg2 | 2.4.4-150600.3.9.1 | SUSE-SU-2025:02259-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | gpg2 | 2.4.4-slfo.1.1_2.1 | SUSE-SU-2025:20472-1, SUSE-SU-2025:20458-1, SUSE-SU-2025:20444-1 |
| SLE Micro 6.0 | gpg2 | 2.4.4-2.1 | SUSE-SU-2025:20465-1, SUSE-SU-2025:20454-1, SUSE-SU-2025:20209-1 |
| SLE Micro 5.5 | gpg2 | 2.2.27-150300.3.13.1 | SUSE-SU-2025:3986-1 |
| SLE Micro 5.4 | gpg2 | 2.2.27-150300.3.13.1 | SUSE-SU-2025:3986-1 |
| SLE Micro 5.3 | gpg2 | 2.2.27-150300.3.13.1 | SUSE-SU-2025:3986-1 |
| SLE Micro 5.2 | gpg2 | 2.2.27-150300.3.13.1 | SUSE-SU-2025:3986-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | gpg2 | 2.5.6-1.1 | openSUSE-SU-2025:15076-1 |
| openSUSE Leap 15.6 | gpg2 | 2.4.4-150600.3.9.1 | SUSE-SU-2025:02259-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | gnupg2 +2 | 2.3.7-1.amzn2023.0.5 | ALAS2023-2025-1107 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | gnupg2 | 2.4.8-1 | — |
| Azure Linux 2 (CBL-Mariner) | gnupg2 | No fix yet | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | gpg +12 | 2.4.8-r1 | — |
Advisories 13
- openSUSE-SU-2025:15076-1 dirmngr-2.5.6-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:3986-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20458-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20465-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20444-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20209-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-RU-2025:20460-1 Recommended update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20472-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20454-1 Security update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:02259-1 Recommended update for gpg2 SUSE / openSUSE Security Updates · Mar 23, 2026
- USN-7412-1 gnupg2 vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- WID-SEC-2025-0600 GnuPG: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Dec 8, 2025
- ALAS2023-2025-1107 Low: gnupg2 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 8, 2025