CVE-2026-4438
5.4
MEDIUM
CVSS 3.1
EPSS 0.07%
Description
Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.
How to fix CVE-2026-4438
To remediate CVE-2026-4438, upgrade the affected package to a fixed version below.
- Debian/glibc—upgrade to 2.36-9+deb12u14 or later
Is CVE-2026-4438 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 2.36-9+deb12u14
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.4 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |