CVE-2026-84201
appium-mcp-server through 0.1.61 fails to validate or normalize file paths in the write_file and write_files_batch tools, allowing attackers to write files outside the intended PROJECT_ROOT directory. Attackers can supply absolute paths or relative paths with parent directory segments to overwrite arbitrary files with the server user's privileges, including shell profiles and configuration files in the home directory.
What this means for your business
- An attacker can use it only with access to the machine itself, without a login, but only after tricking someone into an action such as opening a file or a link.
- FIRST's prediction model gives it a 0.1% chance of attack attempts being seen in the next 30 days, ranking above 4% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- 7.1 (v3.1)
- Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H- CVSS v4
- 6.9
- Weakness
- CWE-22
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-01
- Last modified
- 2026-09-08
- Sources
- NVD
References
- https://github.com/argneshu/appium-mcp-server/blob/92b5c2b325e7bdd124f1f41a6049028b2a44e89c/src/mcp_server.py
- https://github.com/argneshu/appium-mcp-server/blob/92b5c2b325e7bdd124f1f41a6049028b2a44e89c/src/tools/write_files_batch.py
- https://www.npmjs.com/package/appium-mcp-server
- https://www.vulncheck.com/advisories/appium-mcp-server-through-0.1.61-path-traversal-in-write-file-and-write-files-batch