{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-8674", "assignerOrgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "state": "PUBLISHED", "assignerShortName": "glibc", "dateReserved": "2026-05-15T12:15:59.229Z", "datePublished": "2026-09-17T16:54:27.310Z", "dateUpdated": "2026-09-17T16:54:27.310Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "shortName": "glibc", "dateUpdated": "2026-09-17T16:54:27.310Z"}, "title": "Assertion failure in the DNS stub resolver with a long search domain", "datePublic": "2023-11-07T05:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-617", "description": "CWE-617 Reachable Assertion", "type": "CWE"}]}], "affected": [{"vendor": "The GNU C Library", "product": "glibc", "versions": [{"status": "affected", "version": "2.26", "lessThanOrEqual": "2.44", "versionType": "custom"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Initializing the DNS stub resolver from an /etc/resolv.conf file, or a LOCALDOMAIN environment variable, whose search list contains a domain of roughly 200 characters or more in the GNU C Library version 2.26 to 2.44 results in an assertion failure which aborts the process.\n\nThe resolver truncates the search list when copying it into the fixed-size _res.defdname buffer, then asserts that the copy is consistent with the full configuration. The consistency check compared against the wrong size and did not handle a first entry that does not fit, so a correctly truncated list failed the assertion. Any process that resolves names through the library is affected, including long-running processes that reload /etc/resolv.conf on the next query after it changes. Search domains are commonly written to /etc/resolv.conf from data received over DHCP or from a VPN server, so an attacker on the local network may be able to trigger this without privileges on the target system, subject to validation by the network configuration software.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Initializing the DNS stub resolver from an /etc/resolv.conf file, or a LOCALDOMAIN environment variable, whose search list contains a domain of roughly 200 characters or more in the GNU C Library version 2.26 to 2.44 results in an assertion failure which aborts the process.<br><br>The resolver truncates the search list when copying it into the fixed-size _res.defdname buffer, then asserts that the copy is consistent with the full configuration. The consistency check compared against the wrong size and did not handle a first entry that does not fit, so a correctly truncated list failed the assertion. Any process that resolves names through the library is affected, including long-running processes that reload /etc/resolv.conf on the next query after it changes. Search domains are commonly written to /etc/resolv.conf from data received over DHCP or from a VPN server, so an attacker on the local network may be able to trigger this without privileges on the target system, subject to validation by the network configuration software."}]}], "references": [{"url": "https://sourceware.org/bugzilla/show_bug.cgi?id=31026", "tags": ["issue-tracking"]}, {"url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0021", "tags": ["vendor-advisory"]}, {"url": "https://sourceware.org/git/?p=glibc.git;a=commit;h=506ea57086bfb9ce3daff1c14246a1cb532aba0a", "tags": ["patch"]}, {"url": "https://joshua.hu/fuzzing-glibc-libresolv", "tags": ["technical-description"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseSeverity": "MEDIUM", "baseScore": 5.3, "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}}], "credits": [{"lang": "en", "value": "Joshua Rogers", "type": "finder"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.5"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "glibc", "vendor": "The GNU C Library", "versions": [{"lessThanOrEqual": "2.44", "status": "affected", "version": "2.26", "versionType": "custom"}]}], "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Initializing the DNS stub resolver from an /etc/resolv.conf file, or a LOCALDOMAIN environment variable, whose search list contains a domain of roughly 200 characters or more in the GNU C Library version 2.26 to 2.44 results in an assertion failure which aborts the process.\n\nThe resolver truncates the search list when copying it into the fixed-size _res.defdname buffer, then asserts that the copy is consistent with the full configuration. The consistency check compared against the wrong size and did not handle a first entry that does not fit, so a correctly truncated list failed the assertion. Any process that resolves names through the library is affected, including long-running processes that reload /etc/resolv.conf on the next query after it changes. Search domains are commonly written to /etc/resolv.conf from data received over DHCP or from a VPN server, so an attacker on the local network may be able to trigger this without privileges on the target system, subject to validation by the network configuration software."}], "id": "CVE-2026-8674", "lastModified": "2026-09-17T17:16:53.220", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 3.6, "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "type": "Secondary"}]}, "published": "2026-09-17T17:16:53.220", "references": [{"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://joshua.hu/fuzzing-glibc-libresolv"}, {"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=31026"}, {"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0021"}, {"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://sourceware.org/git/?p=glibc.git;a=commit;h=506ea57086bfb9ce3daff1c14246a1cb532aba0a"}], "sourceIdentifier": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-617"}], "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "type": "Secondary"}]}

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