RCE in Crawl4ai
CVE-2026-56264
Crawl4AI before 0.8.7 contains an arbitrary JavaScript execution vulnerability in the Docker API server's /execute_js endpoint, which accepts and executes arbitrary user-supplied JavaScript in the server's browser context with --disable-web-security enabled. An attacker can execute arbitrary JavaScript and, combined with the browser's relaxed security settings, perform server-side request forgery against internal services.
Vulnerability class: RCE (Remote Code Execution)
EPSS: 0.003 (25.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Crawl4ai — versions 0, 0.8.7
- Kidocode Crawl4ai
Weakness classification (CWE)
References
- https://github.com/unclecode/crawl4ai/security/advisories/GHSA-365w-hqf6-vxfg (vendor-advisory, Mitigation, Vendor Advisory)
- https://github.com/unclecode/crawl4ai (Product, product)
- VulnCheck Advisory: Crawl4AI - Arbitrary JavaScript Execution via /execute_js Endpoint (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-56264?
- CVE-2026-56264 is a high-severity vulnerability in Crawl4ai, classified under Code Injection. CVSS score: 8.1/10. Published 2026-06-30.
- How severe is CVE-2026-56264?
- High severity. CVSS v3 base score is 8.1 out of 10.