Vulnerability · Published Jun 23, 2026 · Assigned by GitHub_M
CVE-2026-53754Crawl4AI: SSRF filter bypass in Docker server via IPv6 transition forms (NAT64 / 6to4 / unspecified / v4-mapped)
High 7.5
In plain English
A high-severity server-side request forgery in crawl4ai from unclecode. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Crawl4AI is an open-source LLM friendly web crawler & scraper. Prior to 0.8.8, the Docker API server's SSRF protection (validate_webhook_url / validate_url_destination in deploy/docker/utils.py) used an explicit IPv4/IPv6 CIDR blocklist that missed several address families. An attacker could reach internal services and cloud metadata endpoints (e.g. 169.254.169.254) despite the filter by encoding an internal IPv4 address inside an IPv6 transition form, or by using the IPv6 unspecified address. Because the Docker API is unauthenticated by default (jwt_enabled: false), no credentials are required. This vulnerability is fixed in 0.8.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | crawl4ai | 0.8.8 | GHSA-4qqr-vv2q-cmr5 |
| PyPI | crawl4ai | 0.8.8 | PYSEC-2026-587 |
Affected products (as reported)
Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/unclecode/crawl4ai/security/advisories/GHSA-4qqr-vv2q-cmr5 x_refsource_CONFIRM