{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-18374", "assignerOrgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "state": "PUBLISHED", "assignerShortName": "glibc", "dateReserved": "2026-07-30T10:48:56.220Z", "datePublished": "2026-08-27T19:20:40.426Z", "dateUpdated": "2026-08-27T22:21:53.526Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "shortName": "glibc", "dateUpdated": "2026-08-27T19:26:33.518Z"}, "problemTypes": [{"descriptions": [{"lang": "en", "description": "Buffer overflow in fopen mode argument processing"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-787", "description": "CWE-787 Out-of-bounds write", "type": "CWE"}]}], "impacts": [{"capecId": "CAPEC-100", "descriptions": [{"lang": "en", "value": "CAPEC-100 Overflow Buffers"}]}, {"capecId": "CAPEC-47", "descriptions": [{"lang": "en", "value": "CAPEC-47 Buffer Overflow via Parameter Expansion"}]}], "affected": [{"vendor": "The GNU C Library", "product": "glibc", "versions": [{"status": "affected", "version": "0", "lessThan": "2.45", "versionType": "custom"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Passing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled.\n\n\n\nThis usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Passing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled.\n<br>\n<br>This usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation."}]}], "references": [{"url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34574", "tags": ["issue-tracking"]}, {"url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0015", "tags": ["vendor-advisory"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW", "baseSeverity": "MEDIUM", "baseScore": 4.9, "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L"}}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.5"}}, "adp": [{"title": "CVE Program Container", "references": [{"url": "http://www.openwall.com/lists/oss-security/2026/08/27/6"}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-08-27T22:21:53.526Z"}}]}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "glibc", "vendor": "The GNU C Library", "versions": [{"lessThan": "2.45", "status": "affected", "version": "0", "versionType": "custom"}]}], "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Passing an effectively empty string to the `,ccs=` syntax extension of the mode argument in the `fopen` function in the GNU C Library version 2.45 or earlier may result in a heap buffer overflow when the mode string input to the function is attacker controlled.\n\n\n\nThis usage pattern is not seen in applications in common GNU/Linux distributions and applications that process user-supplied values for `ccs` should not pass them through without validation."}], "id": "CVE-2026-18374", "lastModified": "2026-08-28T00:16:48.620", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "LOW", "baseScore": 4.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L", "version": "3.1"}, "exploitabilityScore": 1.4, "impactScore": 3.4, "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "type": "Secondary"}]}, "published": "2026-08-27T20:17:03.553", "references": [{"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34574"}, {"source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0015"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "http://www.openwall.com/lists/oss-security/2026/08/27/6"}], "sourceIdentifier": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "type": "Secondary"}]}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,2.45)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "glibc", "source": "cna", "vendor": "The GNU C Library"}, "product": "glibc", "vendor": "the_gnu_c_library"}], "created": "2026-08-28T05:30:17.823419+00:00", "updated": "2026-08-28T06:30:18.395916+00:00", "vendors": ["the_gnu_c_library", "the_gnu_c_library$PRODUCT$glibc"]}