Server-Side Request Forgery in Crawl4AI by UncleCode
CVE-2026-56266

9.2CRITICAL

Key Information:

Vendor

Crawl4ai

Status
Crawl4ai
Vendor
CVE Published:
22 June 2026

What is CVE-2026-56266?

Crawl4AI, prior to version 0.8.7, contains a vulnerability that allows unauthenticated attackers to exploit server-side request forgery. This occurs through specific endpoints, including /crawl, /crawl/stream, /md, and /llm, which improperly process user-supplied URLs without adequate validation. By utilizing IPv6-mapped IPv4 addresses, attackers can circumvent the internal-address blocklist, potentially accessing sensitive internal services and cloud metadata endpoints, heightening the risk of unauthorized data exposure.

Affected Version(s)

Crawl4AI 0 < 0.8.7

Crawl4AI 0.8.7

References

https://github.com/unclecode/crawl4ai/security/advisories...
vendor-advisory
https://github.com/unclecode/crawl4ai
product
https://www.vulncheck.com/advisories/crawl4ai-server-side...
third-party-advisory

CVSS V4

Score:
9.2
Severity:
CRITICAL
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.