CVE-2026-6684

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-6684", "assignerOrgId": "44488dab-36db-4358-99f9-bc116477f914", "state": "PUBLISHED", "assignerShortName": "runZero", "dateReserved": "2026-04-20T15:06:20.061Z", "datePublished": "2026-07-01T13:45:03.639Z", "dateUpdated": "2026-07-01T15:25:53.071Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "44488dab-36db-4358-99f9-bc116477f914", "shortName": "runZero", "dateUpdated": "2026-07-01T14:10:58.544Z"}, "title": "FatFs Infinite Loop in GPT Partition Scan", "datePublic": "2026-07-01T13:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-835", "description": "CWE-835 Loop with unreachable exit condition ('infinite loop')", "type": "CWE"}]}], "affected": [{"vendor": "ChaN", "product": "FatFs", "versions": [{"status": "affected", "version": "0", "lessThan": "R0.16", "versionType": "custom"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.<br><br></p>"}]}], "references": [{"url": "https://www.runzero.com/blog/fatfs-bugs/", "tags": ["third-party-advisory"]}, {"url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance", "tags": ["technical-description"]}, {"url": "https://elm-chan.org/fsw/ff/", "tags": ["product"]}, {"url": "https://www.runzero.com/advisories/fatfs-gpt-scan-loop-dos-cve-2026-6684/", "tags": ["third-party-advisory"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "PHYSICAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseSeverity": "MEDIUM", "baseScore": 4.6, "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}], "credits": [{"lang": "en", "value": "HD Moore of runZero, Inc.", "type": "finder"}, {"lang": "en", "value": "Tod Beardsley of runZero, Inc.", "type": "coordinator"}], "source": {"discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.2"}}, "adp": [{"references": [{"url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-07-01T15:25:35.369745Z", "id": "CVE-2026-6684", "options": [{"Exploitation": "poc"}, {"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": "2026-07-01T15:25:53.071Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-6684", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-01T15:25:35.369745Z"}}}], "references": [{"url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-01T15:25:49.136Z"}}], "cna": {"title": "FatFs Infinite Loop in GPT Partition Scan", "source": {"discovery": "UNKNOWN"}, "credits": [{"lang": "en", "type": "finder", "value": "HD Moore of runZero, Inc."}, {"lang": "en", "type": "coordinator", "value": "Tod Beardsley of runZero, Inc."}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.6, "attackVector": "PHYSICAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "ChaN", "product": "FatFs", "versions": [{"status": "affected", "version": "0", "lessThan": "R0.16", "versionType": "custom"}], "defaultStatus": "unaffected"}], "datePublic": "2026-07-01T13:00:00.000Z", "references": [{"url": "https://www.runzero.com/blog/fatfs-bugs/", "tags": ["third-party-advisory"]}, {"url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance", "tags": ["technical-description"]}, {"url": "https://elm-chan.org/fsw/ff/", "tags": ["product"]}, {"url": "https://www.runzero.com/advisories/fatfs-gpt-scan-loop-dos-cve-2026-6684/", "tags": ["third-party-advisory"]}], "x_generator": {"engine": "Vulnogram 1.0.2"}, "descriptions": [{"lang": "en", "value": "FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.", "supportingMedia": [{"type": "text/html", "value": "<p>FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial.<br><br></p>", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-835", "description": "CWE-835 Loop with unreachable exit condition ('infinite loop')"}]}], "providerMetadata": {"orgId": "44488dab-36db-4358-99f9-bc116477f914", "shortName": "runZero", "dateUpdated": "2026-07-01T14:10:58.544Z"}}}, "cveMetadata": {"cveId": "CVE-2026-6684", "state": "PUBLISHED", "dateUpdated": "2026-07-01T15:25:53.071Z", "dateReserved": "2026-04-20T15:06:20.061Z", "assignerOrgId": "44488dab-36db-4358-99f9-bc116477f914", "datePublished": "2026-07-01T13:45:03.639Z", "assignerShortName": "runZero"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "FatFs", "vendor": "ChaN", "versions": [{"lessThan": "R0.16", "status": "affected", "version": "0", "versionType": "custom"}]}], "source": "44488dab-36db-4358-99f9-bc116477f914"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:elm-chan:fatfs:*:*:*:*:*:*:*:*", "matchCriteriaId": "4140C7A2-22F3-4919-AF38-C8F13F12B9F7", "versionEndExcluding": "r0.16", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "FatFs prior to R0.16 that use GPT scanning with 'FF_LBA64 = 1' contains an issue where an unbounded loop count derived from GPT header field GPTH_PtNum, enabling extremely long or effectively infinite mount-time scans. This maps to CWE-835 (Loop with Unreachable Exit Condition). Estimated CVSS v3.1 vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Medium). The estimated CISA SSVC vectors are Exploitation: PoC, Technical Impact: Partial."}, {"lang": "es", "value": "FatFs anterior a R0.16 que utiliza el escaneo GPT con \u2019FF_LBA64 = 1\u2019 contiene un problema donde un conteo de bucle ilimitado derivado del campo de encabezado GPT GPTH_PtNum, lo que permite escaneos en tiempo de montaje extremadamente largos o efectivamente infinitos. Esto se mapea a CWE-835 (Bucle con Condici\u00f3n de Salida Inalcanzable). Vector CVSS v3.1 estimado: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (4.6, Media). Los vectores SSVC de CISA estimados son Explotaci\u00f3n: PoC, Impacto T\u00e9cnico: Parcial."}], "id": "CVE-2026-6684", "lastModified": "2026-10-25T17:10:00.197", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "PHYSICAL", "availabilityImpact": "HIGH", "baseScore": 4.6, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 0.9, "impactScore": 3.6, "source": "44488dab-36db-4358-99f9-bc116477f914", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-6684", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-07-01T15:25:35.369745Z", "version": "2.0.3"}}]}, "published": "2026-07-01T15:17:12.553", "references": [{"source": "44488dab-36db-4358-99f9-bc116477f914", "tags": ["Product"], "url": "https://elm-chan.org/fsw/ff/"}, {"source": "44488dab-36db-4358-99f9-bc116477f914", "tags": ["Third Party Advisory", "Exploit"], "url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance"}, {"source": "44488dab-36db-4358-99f9-bc116477f914", "tags": ["Third Party Advisory"], "url": "https://www.runzero.com/advisories/fatfs-gpt-scan-loop-dos-cve-2026-6684/"}, {"source": "44488dab-36db-4358-99f9-bc116477f914", "tags": ["Third Party Advisory", "Exploit"], "url": "https://www.runzero.com/blog/fatfs-bugs/"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Third Party Advisory", "Exploit"], "url": "https://github.com/runZeroInc/vulns-2026-fatfs-chance"}], "sourceIdentifier": "44488dab-36db-4358-99f9-bc116477f914", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-835"}], "source": "44488dab-36db-4358-99f9-bc116477f914", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,R0.16)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "FatFs", "source": "cna", "vendor": "ChaN"}, "product": "fatfs", "vendor": "chan"}], "created": "2026-07-01T18:30:15.965587+00:00", "updated": "2026-08-01T23:45:03.624736+00:00", "vendors": ["chan", "chan$PRODUCT$fatfs"]}