CVE-2026-53765 ChromeDevTools CVE debrief

Who should care

Defenders responsible for managing and securing Chrome DevTools for agents (chrome-devtools-mcp) installations, particularly in multi-user environments, should assess exposure and prioritize remediation.

Why it matters

CVE-2026-53765 is a medium-severity vulnerability in Chrome DevTools for agents (chrome-devtools-mcp) that allows a local low-privilege user to exploit a symlink vulnerability, potentially leading to data loss or corruption. Defenders should prioritize verifying and upgrading to version 1.1.0 or later, and implement monitoring for potential exploitation attempts.

• A local low-privilege user can truncate a file writable by the victim
• Potential for data loss or corruption
• Need for verifying and upgrading to version 1.1.0 or later
• Importance of monitoring for potential exploitation attempts

Technical summary

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.

Defensive priority

Defenders should prioritize verifying and upgrading to version 1.1.0 or later, and implement monitoring for potential exploitation attempts.

Recommended defensive actions

• Verify and upgrade Chrome DevTools for agents (chrome-devtools-mcp) to version 1.1.0 or later
• Implement monitoring for potential exploitation attempts
• Review and update access controls and file system permissions
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD vulnerability detail page provide information on the vulnerability, including its description, CVSS score, and affected versions. The chrome-devtools-mcp daemon's use of fs.writeFileSync() without O_NOFOLLOW allows a local low-privilege user to exploit a symlink vulnerability. The vulnerability is fixed in version 1.1.0. Defenders should verify and upgrade to the latest version, and implement monitoring for potential exploitation attempts. The CVE Program record and NVD detail page offer source-provided CVE

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.