MEDIUM
CVE-2026-4438
CWE-20Published: March 20, 2026· Updated: Mar 23, 2026
5.4
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:10.8th
Official 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.
Technical Analysis
CVE-2026-4438 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorAdjacent
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
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GitHub PoC Search
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Rapid7 / Metasploit
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PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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All References (1)
Quick Facts
CVE IDCVE-2026-4438
CVSS Score5.4 / 10
SeverityMEDIUM
WeaknessCWE-20
CISA KEVNo
EPSS (30d)0.04%
PublishedMar 20, 2026
Related CVEs (CWE-20)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-4438 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.