{"id":"CVE-2026-85661","title":"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","summary":"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 …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-22"],"vendor":"haris-musa","product":"excel-mcp-server","affected":["excel-mcp-server <= 0.1.8"],"published":"2026-09-04","updated":"2026-09-23","sourceUpdated":"2026-09-23T17:17:45.823","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-85661","references":[{"url":"https://github.com/haris-musa/excel-mcp-server","label":"disclosure@vulncheck.com"},{"url":"https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/server.py","label":"disclosure@vulncheck.com"},{"url":"https://github.com/haris-musa/excel-mcp-server/blob/v0.1.8/src/excel_mcp/validation.py","label":"disclosure@vulncheck.com"},{"url":"https://github.com/haris-musa/excel-mcp-server/issues/149","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/excel-mcp-server-0.1.8-arbitrary-file-read-write-via-stdio-mode","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"epss":0.00441,"epssPercentile":0.3777,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-09-14T19:20:06.345946Z"},"ingestedAt":"2026-09-14T20:14:21.164Z","slug":"CVE-2026-85661","body":"## Overview\n\nexcel-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}