CVE-2026-53754

Crawl4AI: SSRF filter bypass in Docker server via IPv6 transition forms (NAT64 / 6to4 / unspecified / v4-mapped)

State: Published
Severity: 7.5 High
Published: Jun 23, 2026
Updated: Jun 23, 2026
Reserved: Jun 10, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N	GitHub_M

Weaknesses

CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Product	Versions
crawl4aiunclecode	< 0.8.8Affected

References

https://github.com/unclecode/crawl4ai/security/advisories/GHSA-4qqr-vv2q-cmr5

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.