CVE-2026-53755: CWE-918: Server-Side Request Forgery (SSRF) in unclecode crawl4ai
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.
AI Analysis
Technical Summary
In unclecode crawl4ai versions before 0.8.9, the Docker API server's SSRF protection only validated the crawl target URL but failed to validate proxy addresses supplied via various browser and crawler configuration fields. An unauthenticated attacker could exploit this by specifying a proxy server pointing to internal network addresses or cloud metadata endpoints, effectively routing Chromium browser egress traffic through these proxies. This SSRF vulnerability leverages the unauthenticated Docker API and multiple proxy configuration options, including deprecated and extra argument flags. The vulnerability is resolved in version 0.8.9.
Potential Impact
An unauthenticated attacker can exploit this SSRF vulnerability to access internal services and cloud metadata endpoints by routing browser traffic through attacker-controlled proxies pointing to internal IP addresses. This can lead to unauthorized disclosure of sensitive internal information. The vulnerability does not impact integrity or availability but has high confidentiality impact. The Docker API being unauthenticated by default increases the attack surface.
Mitigation Recommendations
This vulnerability is fixed in crawl4ai version 0.8.9. Users should upgrade to version 0.8.9 or later to remediate this issue. No other official remediation or temporary fixes are documented. Until upgrading, restrict access to the Docker API server to trusted users only to reduce exposure.
CVE-2026-53755: CWE-918: Server-Side Request Forgery (SSRF) in unclecode crawl4ai
Description
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.
CVSS v3.1
Score 8.6high
Affected software
pkg:github/unclecode/crawl4aiRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In unclecode crawl4ai versions before 0.8.9, the Docker API server's SSRF protection only validated the crawl target URL but failed to validate proxy addresses supplied via various browser and crawler configuration fields. An unauthenticated attacker could exploit this by specifying a proxy server pointing to internal network addresses or cloud metadata endpoints, effectively routing Chromium browser egress traffic through these proxies. This SSRF vulnerability leverages the unauthenticated Docker API and multiple proxy configuration options, including deprecated and extra argument flags. The vulnerability is resolved in version 0.8.9.
Potential Impact
An unauthenticated attacker can exploit this SSRF vulnerability to access internal services and cloud metadata endpoints by routing browser traffic through attacker-controlled proxies pointing to internal IP addresses. This can lead to unauthorized disclosure of sensitive internal information. The vulnerability does not impact integrity or availability but has high confidentiality impact. The Docker API being unauthenticated by default increases the attack surface.
Mitigation Recommendations
This vulnerability is fixed in crawl4ai version 0.8.9. Users should upgrade to version 0.8.9 or later to remediate this issue. No other official remediation or temporary fixes are documented. Until upgrading, restrict access to the Docker API server to trusted users only to reduce exposure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-10T17:48:40.546Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a3ad655eed863c81e794591
Added to database: 06/23/2026, 18:54:13 UTC
Last enriched: 06/30/2026, 23:02:25 UTC
Last updated: 08/06/2026, 12:41:11 UTC
Views: 90
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