CVE-2026-4437

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

Description The GNU C Library contains a flaw where calling the gethostbyaddr or gethostbyaddr r functions with a specific nsswitch.conf configuration utilizing the library’s DNS backend may lead to a violation of the DNS specification. A crafted response from a configured DNS server could cause the application to incorrectly interpret a non-answer section of the DNS response as a valid answer.

Recommendations Versions prior to 2.34 or after 2.43 should be used.