Executive brief
Crawl4AI is an open-source web crawling and scraping tool designed for use with Large Language Models (LLMs). A security flaw in its Docker API server allows an attacker to write files to any location on the server's filesystem that the application has permission to access. This could be used to overwrite critical system files, leading to a complete shutdown of the service or unauthorized modification of data.
Technical details
An arbitrary file write vulnerability exists in Crawl4AI's Docker API server within the /screenshot and /pdf endpoints. The root cause is a lack of validation for the 'output_path' parameter, which allows attackers to provide absolute paths or path traversal sequences (e.g., '../'). An unauthenticated remote attacker can exploit this to write or overwrite files anywhere the application user has write access. This can result in a Denial of Service (DoS) by overwriting critical configuration or system files. The issue is fixed in version 0.8.7 by implementing path validation that restricts writes to a specific output directory and rejects traversal sequences.
Affected products
- unclecode Crawl4AI < 0.8.7
Timeline
- 2026-06-02: advisory: Vendor security advisory published via GitHub (GHSA-365w-hqf6-vxfg)
- 2026-07-12: disclosed: CVE-2026-56260 published to NVD
- 2026-08-07: patched: Vulnerability fixed in version 0.8.7