dbcve.org
Crawl4aiApplication · Kidocode

CVE-2026-53755

HIGH · 7.5 CVSS v3.1 Published 2026-06-23
Fix available
A fix is available. Upgrade to 0.8.9 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Crawl4AI versions before 0.8.9 have a Server-Side Request Forgery (SSRF) vulnerability where the Docker API server only validated the crawl target URL but not proxy configuration parameters. An unauthenticated attacker can specify an internal-network proxy via browser_config.proxy_config.server, browser_config.proxy, crawler_config.proxy_config.server, or browser_config.extra_args proxy flags to route browser traffic through internal IPs, accessing internal services and cloud-metadata endpoints.

MitigationUpgrade to Crawl4AI version 0.8.9 or later which implements SSRF protection for proxy addresses. Until upgraded, disable unauthenticated Docker API access and consider network segmentation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Crawl4aiApplication
Affected:< 0.8.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Crawl4AI version
    Run 'pip show crawl4ai' or check the container image tag to identify the installed version
    Affected if Version is below 0.8.9 (e.g., 0.8.8, 0.8.7, etc.)
  2. Verify Docker API accessibility
    Check if the Docker socket (/var/run/docker.sock) or Docker TCP port (2375/2376) is exposed to unauthenticated users or untrusted networks
    Affected if Docker API is accessible without authentication from untrusted networks
  3. Inspect proxy configuration endpoints
    Review API request logs or audit crawler configurations for use of proxy parameters: browser_config.proxy_config.server, browser_config.proxy, crawler_config.proxy_config.server, or browser_config.extra_args containing proxy settings
    Affected if Proxy parameters can be controlled by unauthenticated users and point to internal IP addresses (e.g., 127.0.0.1, 10.x.x.x, 172.16.x.x, 192.168.x.x) or cloud metadata endpoints (169.254.169.254)
  4. Check for internal network connections
    Monitor network connections or review Docker/container logs for outbound connections from the Crawl4AI service to internal IPs or metadata endpoints
    Affected if Connections have been made to internal services or cloud metadata endpoints (169.254.169.254) that were not explicitly intended as crawl targets

A user is affected if running Crawl4AI version below 0.8.9 with unauthenticated access to its API, where an attacker can inject internal network proxy settings to reach sensitive internal endpoints.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.8.9 or later
Fixed in 0.8.9
Interim mitigation

Upgrade to Crawl4AI version 0.8.9 or later which implements SSRF protection for proxy addresses. Until upgraded, disable unauthenticated Docker API access and consider network segmentation.

Recommended fix High confidence

0.8.9

  1. Upgrade Crawl4ai to version 0.8.9 or later
  2. If running via Docker, pull the updated image with the fixed version
  3. Restart the Crawl4ai service to apply the update
  4. Verify the upgrade was successful by checking the version number
  5. Ensure the Docker API is properly secured with authentication if exposed to untrusted networks

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Crawl4ai Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53755 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data