{"id":"CVE-2026-85661","aliases":["EUVD-2026-71117","GHSA-xv88-r947-5c3v"],"status":"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.","severity":{"version":"4.0","score":9.3,"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","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00687,"percentile":0.53119,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-22"],"published":"2026-09-04T14:32:18Z","modified":"2026-10-28T02:31:03Z","products":[{"vendor":"haris-musa","product":"excel-mcp-server"}],"references":[{"url":"https://github.com/haris-musa/excel-mcp-server/issues/149","tags":["issue-tracking","report"]},{"url":"https://github.com/haris-musa/excel-mcp-server","tags":["product","package"]},{"url":"https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/server.py","tags":["technical-description","article"]},{"url":"https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/validation.py","tags":["technical-description","article"]},{"url":"https://www.vulncheck.com/advisories/excel-mcp-server-0.1.8-arbitrary-file-read-write-via-stdio-mode","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-85661","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-xv88-r947-5c3v"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85661.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-85661","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.","status":"published","published":"2026-09-04T14:32:18.828Z","modified":"2026-09-14T19:33:09.025Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical","assessor":"cna"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:19:52.410665Z"}],"euvd":[{"id":"EUVD-2026-71117","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.","status":"published","published":"2026-09-04T14:32:18Z","modified":"2026-09-14T19:33:09Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical"}],"updated_at":"2026-11-02T17:28:19.383429Z"}],"ghsa":[{"id":"GHSA-xv88-r947-5c3v","title":"excel-mcp-server 0.1.8 fails to enforce path confinement in stdio mode when EXCEL_FILES_PATH is...","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.","status":"published","published":"2026-09-04T15:36:14Z","modified":"2026-09-04T15:36:23Z","cvss":[{"version":"4.0","score":9.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:11:22.550434Z"}],"nvd":[{"id":"CVE-2026-85661","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.","status":"published","published":"2026-09-04T15:17:43.643Z","modified":"2026-09-23T17:17:45.823Z","cvss":[{"version":"4.0","score":9.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:43.737972Z"}],"osv":[{"id":"CVE-2026-85661","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.","status":"published","published":"2026-09-04T14:32:18.828Z","modified":"2026-10-28T02:31:03.314193657Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:45:18.825071Z"}]}}