What’s Vulnerable › Vulnerabilities
CVE-2026-53765: chrome-devtools-mcp: daemon.pid write follows symlinks in /tmp fallback runtime directory
- Severity: medium (CVSS 6.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.1% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-06-24 · updated 2026-10-25
- Weakness: CWE-59
Description
Chrome DevTools for agents (chrome-devtools-mcp) lets your coding agent control and inspect a live Chrome browser. From 0.20.0 until 1.1.0, The chrome-devtools-mcp daemon writes its PID file with fs.writeFileSync() to a deterministic runtime path. On typical macOS environments, and on Linux sessions where $XDG_RUNTIME_DIR is unset, that runtime path falls back to /tmp/chrome-devtools-mcp-<uid>/daemon.pid. Because the write does not use O_NOFOLLOW, a local low-privilege user on the same POSIX host can pre-create /tmp/chrome-devtools-mcp-<victim_uid>/daemon.pid as a symlink to a file writable by the victim. When the victim later starts daemon mode, fs.writeFileSync() follows the symlink and truncates the target file to the daemon PID string. This vulnerability is fixed in 1.1.0.
Affected products
- ChromeDevTools chrome-devtools-mcp: from 0.20.0 before 1.1.0 — fixed in 1.1.0
How to fix
Upgrade to a fixed version: ChromeDevTools chrome-devtools-mcp 1.1.0. Check the vendor advisory for mitigations.
References
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