# CVE-2026-53765: chrome-devtools-mcp: daemon.pid write follows symlinks in /tmp fallback runtime directory

> A local attacker can overwrite arbitrary files via symlink attacks on the daemon PID file in the temporary directory.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** GHSA-3pvj-jv98-qhjq

## What is CVE-2026-53765?

CVE-2026-53765 is a medium-severity path traversal vulnerability in ChromeDevTools chrome-devtools-mcp, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-53765?

2 open source packages ship an affected version, including chrome-devtools-mcp. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `chrome-devtools-mcp` | npm | From 0.20.0 | 1.1.0 |
| `chrome-devtools-mcp` | npm | From 0.20.0 | 1.1.0 |

Products: Google Chrome-Devtools-Mcp.

## How do I fix CVE-2026-53765?

Upgrade chrome-devtools-mcp to 1.1.0 or later.

## Is CVE-2026-53765 being exploited?

There is no known exploitation of CVE-2026-53765 in the wild and no public exploit code.

## Other vulnerabilities in ChromeDevTools chrome-devtools-mcp

- [CVE-2026-53766](https://insights.sbomify.com/CVE-2026-53766/): chrome-devtools-mcp: validatePath() does not canonicalize symlinks before enforcing roots (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53765 and fix it if it is affected.

What it is: CVE-2026-53765 is a medium-severity path traversal vulnerability in ChromeDevTools chrome-devtools-mcp, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53765 in the wild and no public exploit code.

Affected packages and fixed versions:
- chrome-devtools-mcp (npm): affected from 0.20.0; fixed in 1.1.0
- chrome-devtools-mcp (npm): affected from 0.20.0; fixed in 1.1.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53765/ (Markdown: https://insights.sbomify.com/CVE-2026-53765/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53765
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53765
- OSV: https://osv.dev/vulnerability/CVE-2026-53765

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53765/
Summaries are generated and may contain mistakes; the official description above is the record.