PT-2026-26671 · Gnu · Gnu C Library

Published 2026-01-01 · Updated 2026-03-24 · CVE-2026-4438

Positive Technologies · (AI Summary)

CVSS v3.1

5.4

Medium

AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions GNU C library versions 2.34 through 2.43

Description The GNU C library’s gethostbyaddr and gethostbyaddr r functions, when used with a configured nsswitch.conf file specifying the library’s DNS backend, may return invalid DNS hostnames. This behavior violates the DNS specification.

Recommendations Update the GNU C library to a version later than 2.43.

Fix

RCE

Argument Injection

Weakness Enumeration

CWE-20

CWE-88

Related Identifiers

CVE-2026-4438

Affected Products

Gnu C Library

References · 8

• https://osv.dev/vulnerability/DEBIAN-CVE-2026-4438 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-4438 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-4438 · Vendor Advisory
• https://twitter.com/CVEnew/status/2035262166228488672 · Twitter Post
• https://twitter.com/infoflowcloud/status/2035262947425955943 · Twitter Post
• https://twitter.com/oss_security/status/2036285261521314128 · Twitter Post
• https://twitter.com/cyberbivash/status/2035092460062343373 · Twitter Post
• https://sourceware.org/bugzilla/show_bug.cgi?id=34015 · Note