{"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": "2026-08-28T15:37:10.821Z"}, "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"}}, {"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-787", "lang": "en", "description": "CWE-787 Out-of-bounds Write"}]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-28T15:36:48.992608Z", "id": "CVE-2026-18374", "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": "2026-08-28T15:37:10.821Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"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"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-18374", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-28T15:36:48.992608Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-787", "description": "CWE-787 Out-of-bounds Write"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-28T15:37:06.732Z"}}], "cna": {"source": {"discovery": "UNKNOWN"}, "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"}]}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.9, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "The GNU C Library", "product": "glibc", "versions": [{"status": "affected", "version": "0", "lessThan": "2.45", "versionType": "custom"}], "defaultStatus": "unaffected"}], "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"]}], "x_generator": {"engine": "Vulnogram 1.0.5"}, "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", "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.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Buffer overflow in fopen mode argument processing"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-787", "description": "CWE-787 Out-of-bounds write"}]}], "providerMetadata": {"orgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "shortName": "glibc", "dateUpdated": "2026-08-27T19:26:33.518Z"}}}, "cveMetadata": {"cveId": "CVE-2026-18374", "state": "PUBLISHED", "dateUpdated": "2026-08-28T15:37:10.821Z", "dateReserved": "2026-07-30T10:48:56.220Z", "assignerOrgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "datePublished": "2026-08-27T19:20:40.426Z", "assignerShortName": "glibc"}, "dataVersion": "5.2"}

{"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": "2026-09-03T16:43:15.293", "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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-18374", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-28T15:36:48.992608Z", "version": "2.0.3"}}]}, "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": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-787"}], "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-787"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "glibc: glibc: Heap buffer overflow via attacker-controlled fopen mode string", "id": "2525256", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2525256"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.9", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L", "status": "draft"}, "cwe": "CWE-134", "details": ["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.\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.", "A flaw was found in the GNU C Library (glibc). This vulnerability could allow an attacker with local access to trigger a heap buffer overflow by manipulating how the `fopen` function handles certain input. This could lead to minor disruptions in system operations or limited access to sensitive information."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}, "name": "CVE-2026-18374", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "glibc", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Fix deferred", "package_name": "compat-glibc", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Fix deferred", "package_name": "glibc", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "compat-glibc", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "glibc", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "glibc", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "glibc", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "filesystem", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "glibc", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-08-27T19:20:40Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-18374\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-18374\nhttps://sourceware.org/bugzilla/show_bug.cgi?id=34574\nhttps://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0015"], "statement": "This vulnerability in glibc involves a heap buffer overflow when the `fopen` function processes an attacker-controlled mode string with an effectively empty `,ccs=` extension. Exploitation is highly complex as this specific usage pattern is not common in applications within typical Red Hat Enterprise Linux environments, significantly limiting its practical applicability.", "threat_severity": "Moderate"}