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MEDIUM · 5.4

CVE-2026-4438

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 hostn...

Vulnerability 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.

CVSS Score

5.4

MEDIUM

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack Vector
ADJACENT_NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE

Affected Products

VendorProductVersions
GnuGlibc>= 2.34, <= 2.43

Related Weaknesses (CWE)

CWE-20CWE-88

References

FAQ

What is CVE-2026-4438?

CVE-2026-4438 is a vulnerability with a CVSS score of 5.4 (MEDIUM). 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 hostn...

How severe is CVE-2026-4438?

CVE-2026-4438 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-4438?

Check the references section above for vendor advisories and patch information. Affected products include: Gnu Glibc.