CVE-2026-109239 unclecode CVE debrief

Who should care

Defenders responsible for Crawl4AI instances, especially those with Docker server egress controls, should assess exposure and potential impact. They should verify exposure of Crawl4AI instances, assess potential service discovery by attackers, and update to version 0.9.4 or later. Additionally, defenders should review compensating controls for exposed systems while remediation is scheduled and verified, and check relevant monitoring, detection, and logs

Why it matters

CVE-2026-109239 is a medium-severity vulnerability in Crawl4AI that allows attackers to bypass Docker server egress controls. Defenders should verify exposure, assess potential impact, and update to version 0.9.4 or later.

• Service discovery by attackers
• Potential bypass of Docker server egress controls
• Unauthenticated access to internal or loopback addresses
• Possible exploitation for further attacks

Technical summary

The vulnerability is caused by a blind server-side request forgery (SSRF) in the RobotsParser.can_fetch function of Crawl4AI before 0.9.4. This allows unauthenticated attackers to bypass Docker server egress controls by enabling check_robots_txt and using redirects or DNS rebinding to reach internal, loopback, or cloud-metadata addresses for service discovery. The vulnerability has a medium severity and defenders should prioritize verifying exposure of Crawl4AI instances, especially those with Docker server egress controls, and assess the impact of potential service discovery by attackers.

Defensive priority

Defenders should prioritize verifying exposure of Crawl4AI instances, especially those with Docker server egress controls, and assess the impact of potential service discovery by attackers.

Recommended defensive actions

• Verify Crawl4AI instance exposure, especially those with Docker server egress controls
• Assess potential service discovery by attackers
• Update Crawl4AI to version 0.9.4 or later
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the vulnerability in Crawl4AI before 0.9.4, specifically a blind server-side request forgery (SSRF) vulnerability in the RobotsParser.can_fetch function. Limited information is available on potential exploitation or affected systems. Defenders should verify exposure of Crawl4AI instances, especially those with Docker server egress controls, assess potential service discovery by attackers, and monitor for potential exploitation attempts. The vulnerability allows unauthenticated attacks,

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.