{"id":"CVE-2026-85661","state":"PUBLISHED","title":"excel-mcp-server 0.1.8 Arbitrary File Read/Write via stdio mode","description":"excel-mcp-server 0.1.8 fails to enforce path confinement in stdio mode when EXCEL_FILES_PATH is unset, allowing attackers to read and write arbitrary files. Attackers can supply unchecked file paths to read and write tools to access any file accessible to the process.","publishedAt":"2026-09-04T14:32:18.828Z","updatedAt":"2026-09-14T19:33:09.025Z","severity":{"score":9.3,"label":"Critical","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["haris-musa excel-mcp-server"],"affected":[{"vendor":"haris-musa","product":"excel-mcp-server","packageURL":"pkg:pypi/excel-mcp-server","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"0.1.8","versionType":"semver"}]}],"references":["https://github.com/haris-musa/excel-mcp-server/issues/149","https://github.com/haris-musa/excel-mcp-server","https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/server.py","https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/validation.py","https://www.vulncheck.com/advisories/excel-mcp-server-0.1.8-arbitrary-file-read-write-via-stdio-mode"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/85xxx/CVE-2026-85661.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-85661","state":"PUBLISHED","datePublished":"2026-09-04T14:32:18.828Z","dateUpdated":"2026-09-14T19:33:09.025Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-04T13:32:27.956Z"},"containers":{"cna":{"title":"excel-mcp-server 0.1.8 Arbitrary File Read/Write via stdio mode","descriptions":[{"lang":"en","value":"excel-mcp-server 0.1.8 fails to enforce path confinement in stdio mode when EXCEL_FILES_PATH is unset, allowing attackers to read and write arbitrary files. Attackers can supply unchecked file paths to read and write tools to access any file accessible to the process."}],"affected":[{"vendor":"haris-musa","product":"excel-mcp-server","packageURL":"pkg:pypi/excel-mcp-server","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"0.1.8","versionType":"semver"}]}],"references":[{"url":"https://github.com/haris-musa/excel-mcp-server/issues/149","tags":["issue-tracking"],"name":"GitHub Issue #149"},{"url":"https://github.com/haris-musa/excel-mcp-server","tags":["product"]},{"url":"https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/server.py","tags":["technical-description"]},{"url":"https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/validation.py","tags":["technical-description"]},{"url":"https://www.vulncheck.com/advisories/excel-mcp-server-0.1.8-arbitrary-file-read-write-via-stdio-mode","name":"VulnCheck Advisory: excel-mcp-server 0.1.8 Arbitrary File Read/Write via stdio mode","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":9.8,"baseSeverity":"CRITICAL"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-09-04T14:32:18.828Z"},"datePublic":"2026-07-08T00:00:00.000Z","credits":[{"lang":"en","value":"George Chen","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-85661","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-09-14T19:20:06.345946Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-14T19:33:09.025Z"}}]}}}