{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-4438","assignerOrgId":"3ff69d7a-14f2-4f67-a097-88dee7810d18","state":"PUBLISHED","assignerShortName":"glibc","dateReserved":"2026-03-19T19:55:44.639Z","datePublished":"2026-03-20T19:59:06.064Z","dateUpdated":"2026-03-23T15:06:16.376Z"},"containers":{"cna":{"providerMetadata":{"orgId":"3ff69d7a-14f2-4f67-a097-88dee7810d18","shortName":"glibc","dateUpdated":"2026-03-20T19:59:06.064Z"},"title":"gethostbyaddr and gethostbyaddr_r return invalid DNS hostnames","datePublic":"2026-03-20T22:17:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-20","description":"CWE-20 Improper input validation","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-142","descriptions":[{"lang":"en","value":"CAPEC-142 DNS Cache Poisoning"}]}],"affected":[{"vendor":"The GNU C Library","product":"glibc","versions":[{"status":"affected","version":"2.34","lessThanOrEqual":"2.43","versionType":"custom"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"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.","supportingMedia":[{"type":"text/html","base64":false,"value":"<div>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.</div>"}]}],"references":[{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=34015"}],"credits":[{"lang":"en","value":"Antonio Maini (0rbitingZer0) - 0rbitingZer0@proton.me","type":"finder"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.1"}},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-88","lang":"en","description":"CWE-88 Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')"}]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.4,"attackVector":"ADJACENT_NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-03-23T15:06:13.636418Z","id":"CVE-2026-4438","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-23T15:06:16.376Z"}}]}}