CVE-2026-56266
Summary
Multiple security vulnerabilities in the Crawl4AI Docker API server affecting endpoints for crawling, markdown/LLM extraction, screenshots, PDFs, webhooks, monitoring, JavaScript execution, and configuration.
Vulnerabilities
1. Arbitrary File Write via /screenshot and /pdf (CWE-22, CVSS 9.1)
The output_path parameter accepts arbitrary filesystem paths with no validation. An attacker can overwrite server files (DoS) or write to any appuser-writable location.
Fix: Added validate_output_path() restricting writes to CRAWL4AI_OUTPUT_DIR (/tmp/crawl4ai-outputs by default). Added Pydantic field_validator rejecting .. traversal sequences.
2. SSRF via Webhook URL (CWE-918, CVSS 8.6)
Webhook URLs in /crawl/job and /llm/job accept internal/private IPs with no validation, enabling Server-Side Request Forgery against cloud metadata endpoints (169.254.169.254), internal services, and Docker networks.
Fix: Added validate_webhook_url() with blocklist for RFC 1918, loopback, link-local, cloud metadata IPs and hostnames. Validation at both job submission and send time. Explicit follow_redirects=False.
3. Authentication Bypass on Monitor Endpoints (CWE-306, CVSS 6.5)
The monitor router was mounted without token_dep dependency, making all monitoring endpoints (including destructive ones like /monitor/actions/cleanup) accessible without authentication.
Fix: Added dependencies=[Depends(token_dep)] to monitor router. Added explicit token check on WebSocket /monitor/ws endpoint.
4. Stored XSS in Monitor Dashboard (CWE-79, CVSS 6.1)
URLs and error messages rendered in the monitor dashboard via innerHTML without escaping, enabling stored XSS via crafted crawl URLs.
Fix: Server-side html.escape() on URL and error storage. Client-side escapeHtml() wrapper on all innerHTML template injections.
5. Arbitrary JavaScript Execution via /execute_js (CWE-94, CVSS 8.1)
The /execute_js endpoint accepts and executes arbitrary JavaScript in the server's browser with --disable-web-s
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Exploitation outlook
- Low exploitation risk0.48% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all EPSS-scored CVEs.
Advisory coverage (1)
External references
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