CVE-2026-42013
8.2
HIGH
CVSS 3.1
EPSS 0.05%
Description
A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.
How to fix CVE-2026-42013
To remediate CVE-2026-42013, upgrade the affected package to a fixed version below.
- —upgrade to 3.8.13-r0 or later
- —upgrade to 3.7.1-5+deb11u10 or later
Is CVE-2026-42013 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 3.8.13-r0
- from 0, < 3.7.1-5+deb11u10
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N |