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Medium · 6.1 CVE-2026-53765 EUVD-2026-39105GHSA-3pvj-jv98-qhjq

chrome-devtools-mcp: daemon.pid write follows symlinks in /tmp fallback runtime directory

Published Jun 24, 2026 · Updated Jun 26, 2026 · Assigned by GitHub_M

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

VendorProductAffectedFixed
ChromeDevTools chrome-devtools-mcp >= 0.20.0, < 1.1.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm chrome-devtools-mcp >= 0.20.0, < 1.1.0 1.1.0 GHSA-3pvj-jv98-qhjq

References