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CVE-2026-4438

Severity CVSS v4.0:
Pending analysis
Type:
CWE-20 Input Validation
Publication date:
20/03/2026
Last modified:
07/04/2026

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.

Impact

Vector 3.x
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.40 MEDIUM
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): Low
Availability (A): None

Base Score 3.x
5.40
Severity 3.x
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:* 2.34 (including) 2.43 (including)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools