Crawl4AI: SSRF via proxy settings in the Docker server bypasses the crawl-URL SSRF check
CVE-2026-53755GHSA-6qhc-x826-342c
What to do
Vendor fix available. Upgrade each affected package to the fixed version on its release line (crawl4ai 0.8.9), redeploy, then verify what is actually installed.
This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.
Affected packages
PyPI crawl4ai
- Affected
- <= 0.8.8
- Fixed in
- 0.8.9
Sources
- Open Source Vulnerabilities (OSV.dev), including the GitHub Advisory Database
OSV record GHSA-6qhc-x826-342c lists affected ranges: PyPI crawl4ai >=0 <0.8.9 (fixed)
VerifiedObserved Structured OSV record; GitHub-reviewed advisory.
- GitHub Advisory Database and maintainer security advisories on GitHub
GitHub-reviewed advisory GHSA-6qhc-x826-342c lists affected ranges: PyPI crawl4ai >=0 <=0.8.8
VerifiedObserved Structured GitHub Advisory Database record (type=reviewed) from the GitHub REST API.
Severity and exploitation
- Exploitation
- No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
- CVSS
- 8.6 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- EPSS
- CVE-2026-53755: 1.58% estimated exploitation activity in the next 30 days; percentile 75.50 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description
As published by the source; long descriptions are shortened.
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 browserconfig (and crawlerconfig). The following all feed Chromium's egress and were unchecked: - browserconfig.proxyconfig.server - browserconfig.proxy (deprecated field) - crawlerconfig.proxyconfig.server - --proxy-server / --proxy-pac-url / --proxy-bypass-list / --host-resolver-rules flags in browserconfig.extraargs Attack An attacker sends /crawl with a benign, validation-passing URL but a proxyconfig.server pointing at an internal IP. Chromium routes all requests through that proxy. For plain-HTTP targets the proxy receives the full request and can…
Dates and revisions
- Published by the source
- Last modified by the source
- Source last checked
- Revision 2 · amended ·
Amended from ghsa record GHSA-6qhc-x826-342c
- Revision 1 · created ·
Published from osv record GHSA-6qhc-x826-342c
Agent brief
Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.
# Patch Next advisory brief: CVE-2026-53755 Advisory: Crawl4AI: SSRF via proxy settings in the Docker server bypasses the crawl-URL SSRF check IDs: CVE-2026-53755, GHSA-6qhc-x826-342c Record: https://patchnext.com/advisories/cve-2026-53755 (revision 2, source checked 26 Oct 2026, 13:49 UTC) Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected. Severity: High (CVSS 8.6) Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV. Vendor response: Vendor fix available; fixed versions by package: crawl4ai 0.8.9. A vendor fix does not mean a deployment is fixed. ## Affected components - PyPI crawl4ai: affected <= 0.8.8; fixed in 0.8.9 ## Suggested inspection (read-only) - `python -m pip show crawl4ai`: prints the installed version. Run with the environment that serves production active. ## Supported action Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version. ## Required regression checks - Run the test suite and a production build. - Exercise the features that depend on crawl4ai. - Repeat the inspection and confirm that only fixed versions remain installed. ## Rollback considerations - Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward. ## Unresolved questions - Which deployments run an affected version? - Exploitation status can change. Check again before lowering the priority. - Mark the work resolved only after the fixed version is verified in production. ## Sources - Verified: https://osv.dev/vulnerability/GHSA-6qhc-x826-342c (OSV record GHSA-6qhc-x826-342c lists affected ranges: PyPI crawl4ai >=0 <0.8.9 (fixed)) - Verified: https://github.com/advisories/GHSA-6qhc-x826-342c (GitHub-reviewed advisory GHSA-6qhc-x826-342c lists affected ranges: PyPI crawl4ai >=0 <=0.8.8) Commands are suggestions: review each one before running it.
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