{"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": "2026-03-20T19:59:06.064Z"}, "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"}}}}

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{"cveTags": [], "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."}], "id": "CVE-2026-4438", "lastModified": "2026-03-20T20:16:49.623", "metrics": {}, "published": "2026-03-20T20:16:49.623", "references": [{"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34015"}], "sourceIdentifier": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}], "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "type": "Secondary"}]}

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