| Name | CVE-2026-42010 |
| Description | A flaw was found in gnutls. Servers configured with RSA-PSK (Rivest–Shamir–Adleman – Pre-Shared Key) wrongfully matched usernames containing a NUL character with truncated usernames. A remote attacker could exploit this by sending a specially crafted username, leading to an authentication bypass. This vulnerability allows an attacker to gain unauthorized access by circumventing the authentication process. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-4595-1, DSA-6281-1 |
| Debian Bugs | 1135319 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| gnutls28 (PTS) | bullseye | 3.7.1-5+deb11u5 | vulnerable |
| bullseye (security) | 3.7.1-5+deb11u10 | fixed | |
| bookworm | 3.7.9-2+deb12u6 | vulnerable | |
| bookworm (security) | 3.7.9-2+deb12u7 | fixed | |
| trixie | 3.8.9-3+deb13u3 | vulnerable | |
| trixie (security) | 3.8.9-3+deb13u4 | fixed | |
| forky, sid | 3.8.13-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| gnutls28 | source | bullseye | 3.7.1-5+deb11u10 | DLA-4595-1 | ||
| gnutls28 | source | bookworm | 3.7.9-2+deb12u7 | DSA-6281-1 | ||
| gnutls28 | source | trixie | 3.8.9-3+deb13u4 | DSA-6281-1 | ||
| gnutls28 | source | (unstable) | 3.8.13-1 | 1135319 |
https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-4
https://gitlab.com/gnutls/gnutls/-/issues/1850
Fixed by: https://gitlab.com/gnutls/gnutls/-/commit/cb1833afd9b6309563211b1c0a7c291f52ca98d5 (3.8.13)
Introduced with: https://gitlab.com/gnutls/gnutls/-/commit/d00638997fa269a975095d852633b48b2b64fbf9 (3.6.13)