SSRF in Kidocode Crawl4ai
CVE-2026-53755
Crawl4AI is an open-source LLM friendly web crawler & scraper. Prior to 0.8.9, the Docker API server applied its SSRF destination check to the crawl target URL only, not to the proxy address. An unauthenticated request could supply a proxy pointing at an internal IP and route the browser through it, reaching internal services and cloud-metadata endpoints, while using a perfectly valid crawl URL. The Docker API is unauthenticated by default. /crawl, /crawl/stream, and /crawl/job accept a browser_config (and crawler_config). The following all feed Chromium's egress and were unchecked: browser_config.proxy_config.server, browser_config.proxy (deprecated field), crawler_config.proxy_config.server, and --proxy-server / --proxy-pac-url / --proxy-bypass-list / --host-resolver-rules flags in browser_config.extra_args. This vulnerability is fixed in 0.8.9.
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.016 (74.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.
Affected products
- Kidocode Crawl4ai
- Unclecode Crawl4ai — versions < 0.8.9
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-53755?
- CVE-2026-53755 is a high-severity vulnerability in Kidocode Crawl4ai, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.6/10. Published 2026-06-23.
- How severe is CVE-2026-53755?
- High severity. CVSS v3 base score is 8.6 out of 10.