CVE-2026-85661
CVE-2026-85661
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.
Vulnerability class: Path Traversal (Directory Traversal)
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-85661?
- CVE-2026-85661 is a critical-severity vulnerability, classified under Path Traversal. CVSS score: 9.8/10. Published 2026-09-04.
- How severe is CVE-2026-85661?
- Critical severity. CVSS v3 base score is 9.8 out of 10.