high CVSS 8.6

CVE-2026-53755·Docker vulnerability

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.

Severity
high
Software
Docker
Fixed in
0.8.9
Published
2026-06-23

Affected versions

Until: 0.8.9

Fixed in: 0.8.9

How to fix this CVE

Update Docker to the latest version to patch the SSRF vulnerability in Crawl4AI's API server. The vulnerability allows unauthenticated attackers to bypass destination validation by routing requests through proxy configurations, potentially exposing internal services and cloud metadata endpoints. Upgrade to version 0.8.9 or later immediately, and review any Docker deployments exposing the /crawl, /crawl/stream, or /crawl/job endpoints without authentication controls.

sudo dnf update docker-ce

Defensia detects this vulnerability

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

POST /crawl HTTP/1.1 with JSON payload containing proxy_config.server, proxy, or extra_args fields pointing to non-routable IP ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) or cloud metadata endpoints (169.254.169.254); also monitor for proxy_pac_url, proxy_bypass_list, or host_resolver_rules parameters with suspicious values.

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch. 

Implement authentication on all Crawl4AI API endpoints (/crawl, /crawl/stream, /crawl/job) using API keys or OAuth; validate and whitelist proxy addresses against an internal registry before accepting requests; block requests containing proxy_config, proxy, extra_args, proxy_pac_url, or host_resolver_rules parameters unless from trusted sources; log all requests with proxy parameters for anomaly detection.

How to check if you are affected

  1. Run `docker --version` to check your installed Docker version; versions prior to 0.8.9 are vulnerable if Crawl4AI is deployed.
  2. Check if Crawl4AI is running by executing `docker ps | grep crawl4ai` and inspect container logs with `docker logs <container_id> | grep -i proxy`.
  3. Review Docker daemon configuration and environment variables for proxy_config, proxy_server, or proxy settings: `env | grep -i proxy` and inspect mounted volumes for crawler configuration files.
  4. After patching, verify the update with `docker --version` and confirm Crawl4AI version is 0.8.9+ by checking the container image tag or running `curl http://localhost:8000/health` if the API is accessible.

FAQ

What is CVE-2026-53755?

CVE-2026-53755 is a Server-Side Request Forgery (SSRF) vulnerability in Crawl4AI's Docker API server that fails to validate proxy addresses supplied in browser and crawler configurations, allowing unauthenticated attackers to route requests through internal proxies to reach restricted services and cloud metadata endpoints.

Is CVE-2026-53755 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities catalog and no public exploits are available, but the unauthenticated nature of the vulnerable endpoints makes it a high-risk exposure if the API is internet-facing.

What versions of Docker are affected by CVE-2026-53755?

All versions of Crawl4AI prior to 0.8.9 are affected when deployed in Docker; update to 0.8.9 or later to remediate the proxy validation bypass.

How do I check if my server is vulnerable to CVE-2026-53755?

Run `docker images | grep crawl4ai` to list deployed images and check their tags; if any version is below 0.8.9, the deployment is vulnerable. Additionally, test accessibility of the API endpoints: `curl -X POST http://localhost:8000/crawl -H 'Content-Type: application/json' -d '{"url": "http://example.com"}' | grep -i error` to confirm if the API is exposed.

Does Defensia detect CVE-2026-53755?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Docker or Crawl4AI containers are running on a monitored server, CVE-2026-53755 will appear in your dashboard with remediation steps and version comparison details.

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CVE-2026-42298CVSS 10Postiz is an AI social media scheduling tool. Prior to commit da44801, a "Pwn Request" vulnerability in the Build and Publish PR Docker Image workflow (.github/workflows/pr-docker-build.yml) allows any unauthenticated user to execute arbitrary code during the Docker build process and exfiltrate a highly privileged GITHUB_TOKEN (write-all permissions). This can be achieved simply by opening a Pull Request from a fork with a maliciously modified Dockerfile.dev. This issue has been patched via commit da44801.
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References

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