PyPI: crawl4ai
CVE-2026-53754
Safety vulnerability ID: SFTY-20260616-66519
Affected versions of the Crawl4AI package are vulnerable to Server-Side Request Forgery (SSRF) due to an incomplete IPv4/IPv6 CIDR blocklist. The `validate_webhook_url` and `validate_url_destination` functions in `deploy/docker/utils.py` fail to account for several IPv6 transition forms, allowing internal IP addresses to bypass the blocklist. An unauthenticated attacker can exploit this vulnerability by encoding internal IPv4 addresses within IPv6 transition forms to access internal services and cloud metadata endpoints, potentially exposing sensitive information.
Overview
Crawl4AI: SSRF filter bypass in Docker server via IPv6 transition forms (NAT64 / 6to4 / unspecified / v4-mapped)
Advisory
Crawl4AI – Server-Side Request Forgery (SSRF)
How to Fix
Mitigation and Workarounds
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Vulnerable Functions
Functions linked to known vulnerabilities.
References
- https://getsafety.com/vulnerabilities/SFTY-20260616-66519/CVE-2026-53754
- https://github.com/unclecode/crawl4ai/security/advisories/GHSA-4qqr-vv2q-cmr5
- https://nvd.nist.gov/vuln/detail/CVE-2026-53754
- https://github.com/pypa/advisory-database/tree/main/vulns/crawl4ai/PYSEC-2026-587.yaml
- https://github.com/advisories/GHSA-4qqr-vv2q-cmr5
Verified by Safety
Our Cybersecurity Intelligence Team reviewed this vulnerability. We combine public data with our own research to find issues not yet reported to public sources.
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