Home/CVE/Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the
CVE

CVE-2026-4438

Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the

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.

MEDIUM · CVSS 5.4 EPSS 0.00066
Schedule remediation
  • Public exploit or PoC is available
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-20Improper Input Validation
CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
▤

Affected Products & Versions

1
gnu glibc>= 2.34 and <= 2.43
⚠

Public Exploits & PoCs

1
pocsourceware.org · show_bug.cgi?id=34015sourceware.org
▣

Scoring & Timeline

5.4
MEDIUM · CVSS v3.1 · 3ff69d7a-14f2-4f67-a097-88dee7810d18
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD20 Mar 2026 · 08:16 PM
CVSS VectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

12
suse-csafopenSUSE-SU-2026:10662-1
rhsaRHSA-2026:22634Important
suse-csafSUSE-SU-2026:1369-1
suse-csafopenSUSE-SU-2026:20501-1
suse-csafSUSE-SU-2026:21019-1
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
NVDCVE.orgCISAVulnersExploit-DBGitHub PoCVulnCheck KEVGreyNoise
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin