Description
In GnuPG through 2.4.8, if a signed message has \f at the end of a plaintext line, an adversary can construct a modified message that places additional text after the signed material, such that signature verification of the modified message succeeds (although an "invalid armor" message is printed during verification). This is related to use of \f as a marker to denote truncation of a long plaintext line.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| GnuPG | GnuPG | ≤ 2.4.8 | — |
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 | No fix yet | — |
| Debian 13 | gnupg2 | No fix yet | — |
| Debian 12 | gnupg2 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | gnupg2 +10 | 2.4.9-5.1.hum1 | RHSA-2026:7458 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | gnupg | 2.4.9-r0 | — |
| Alpine v3.23 | gnupg | 2.4.9-r0 | — |
| Alpine v3.22 | gnupg | 2.4.9-r0 | — |
| Alpine v3.21 | gnupg | 2.4.9-r0 | — |
| Alpine v3.20 | gnupg | 2.4.9-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | gnupg2 | 2.4.9-1 | — |
| Azure Linux 2 (CBL-Mariner) | gnupg2 | No fix yet | — |
Advisories 3
- WID-SEC-2026-2189 Dell PowerProtect Data Domain: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 2, 2026
- RHSA-2026:7458 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 6, 2026
- WID-SEC-2025-2928 GnuPG: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 3, 2026