chrome-devtools-mcp: validatePath() does not canonicalize symlinks before enforcing roots
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.24.0 until 1.1.0, McpContext.validatePath() enforces workspace roots by checking whether path.resolve(filePath) textually falls under one of the configured root paths. path.resolve() does not canonicalize symbolic links. As a result, a symlink inside a configured workspace root can point to a file outside that root, pass validation, and then be followed by downstream file read/write operations. This bypass applies even when the MCP client correctly declares the roots capability with a non-empty list. It is separate from the documented legacy behavior where missing roots capability allows all paths. The practical impact is a workspace-boundary bypass. In the write direction, filePath-writing tools can overwrite out-of-root files through an in-root symlink. In the read direction, upload_file can read through the symlink and send the file to the currently selected web page. This vulnerability is fixed in 1.1.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ChromeDevTools | chrome-devtools-mcp | 0.24.0 to before 1.1.0 | 1.1.0 | Patch available | CNA |
| — | chrome-devtools-mcp (npm) | 0.24.0 to before 1.1.0 | 1.1.0 | Patch available | GHSA-8qf9-62x2-82pp |
- chrome-devtools-mcp VendorChromeDevTools Affected 0.24.0 to before 1.1.0 Fixed in 1.1.0 Patch available CNA
- chrome-devtools-mcp (npm) Vendor— Affected 0.24.0 to before 1.1.0 Fixed in 1.1.0 Patch available GHSA-8qf9-62x2-82pp
Remediation
- Fix · CNA chrome-devtools-mcp (ChromeDevTools) Fixed in 1.1.0
- Fix · GHSA-8qf9-62x2-82pp chrome-devtools-mcp (npm) Fixed in 1.1.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53766
- 2026-10-03 Alias added: GHSA-8qf9-62x2-82pp
References
Exploit 1
Other 4
- https://github.com/ChromeDevTools/chrome-devtools-mcp/pull/2127
- https://github.com/ChromeDevTools/chrome-devtools-mcp/commit/176eb695137d9c46a61e2d4d5571880c5145cf46
- https://github.com/ChromeDevTools/chrome-devtools-mcp
- https://github.com/ChromeDevTools/chrome-devtools-mcp/releases/tag/chrome-devtools-mcp-v1.1.0
More Google Chrome-devtools-mcp vulnerabilities
- TI-2026-38771 chrome-devtools-mcp: daemon.pid write follows symlinks in /tmp fallback runtime directory CVSS 3.1MEDIUM 6.1
Sources
- CVE-2026-53766 · CVE Program
- CVE-2026-53766 · NVD
- FIRST EPSS
- GHSA-8qf9-62x2-82pp · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences