CVE-2026-42012
Publication date 30 April 2026
Last updated 27 May 2026
Ubuntu priority
Description
A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted certificate that contains Uniform Resource Identifier (URI) or Service (SRV) Subject Alternative Names (SANs). This could cause the certificate validation process to incorrectly fall back to checking DNS hostnames against the Common Name (CN), potentially allowing the attacker to spoof legitimate services or intercept sensitive information.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| gnutls28 | 26.04 LTS resolute |
Fixed 3.8.12-2ubuntu1.1
|
| 25.10 questing |
Fixed 3.8.9-3ubuntu2.2
|
|
| 24.04 LTS noble |
Fixed 3.8.3-1.1ubuntu3.6
|
|
| 22.04 LTS jammy |
Fixed 3.7.3-4ubuntu1.9
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
7.1 · High
|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity impact | High |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-8284-1
- GnuTLS vulnerabilities
- 20 May 2026