CVE-2026-53755: Crawl4AI: SSRF via proxy settings in the Docker server bypasses the crawl-URL SSRF check

Summary 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 t…

8.6CVSS Score

HIGHSeverity

NOCISA KEV

VulnerabilityImpact Type

📋 Vulnerability Details

CVE ID	CVE-2026-53755
Vendor	pip
Affected Product	crawl4ai
Vulnerability Type	Vulnerability
CVSS Score	8.6 (HIGH)
Actively Exploited	❌ No known exploitation
Patch Status	See Vendor Advisory →
Reported By	CYBERDUDEBIVASH SENTINEL APEX Intelligence (via github_advisories)

🔬 Technical Analysis

Summary 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.

Affected paths `/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

• --proxy-server / --proxy-pac-url / --proxy-bypass-list / --host-resolver-rules flags in browser_config.extra_args

📚 Advisory References

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