---
id: CVE-2026-55557
title: >-
  browse-mcp is a Playwright-based headless-browser MCP server for MCP-capable
  agents
summary: >-
  browse-mcp is a Playwright-based headless-browser MCP server for MCP-capable
  agents. Prior to 0.8.2, browser_download writes a fetched response body to
  join(save_dir, filename) without validating the caller-controlled save_dir,
  while bro…
severity: high
cwe:
  - CWE-22
vendor: browse-mcp
product: browse-mcp
affected:
  - browse-mcp <= 0.8.1
patched:
  - browse-mcp 0.8.2
published: '2026-08-25'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:07:31.353'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55557'
references:
  - url: >-
      https://github.com/That1Drifter/browse-mcp/blob/v0.8.2/CHANGELOG.md#082---2026-06-13
    label: security-advisories@github.com
  - url: >-
      https://github.com/That1Drifter/browse-mcp/commit/5352a4a56f626254b445bfa07e4bb48c5aad15c1
    label: security-advisories@github.com
  - url: 'https://github.com/That1Drifter/browse-mcp/pull/58'
    label: security-advisories@github.com
  - url: 'https://github.com/That1Drifter/browse-mcp/releases/tag/v0.8.2'
    label: security-advisories@github.com
  - url: >-
      https://github.com/That1Drifter/browse-mcp/security/advisories/GHSA-m9mq-7m7q-xc6p
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-m9mq-7m7q-xc6p'
tags:
  - nvd
  - ghsa
  - npm
epss: 0.00238
epssPercentile: 0.13206
aliases:
  - GHSA-m9mq-7m7q-xc6p
ecosystem: npm
ingestedAt: '2026-08-25T17:29:32.244Z'
---

## Overview

browse-mcp is a Playwright-based headless-browser MCP server for MCP-capable agents. Prior to 0.8.2, browser_download writes a fetched response body to join(save_dir, filename) without validating the caller-controlled save_dir, while browser_save_state and browser_load_state honor a caller-controlled path unchanged. A malicious MCP client, or an autonomous agent steered by indirect prompt injection on a visited page, can choose an arbitrary save_dir or state path and a URL whose response body becomes attacker-controlled file contents, allowing writes to any path the process can reach, including ~/.bashrc, autostart entries, or cron files, and potentially leading to host code execution. The force_fetch fallback also uses a raw fetch() that bypasses the BROWSE_MCP_ALLOWED_ORIGINS origin fence. This issue is fixed in version 0.8.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-55557)

Affected packages:

- `browse-mcp <= 0.8.1`

Patched in:

- `browse-mcp 0.8.2`

Source: https://github.com/advisories/GHSA-m9mq-7m7q-xc6p