CVE-2026-119119: Crawl4AI before 0.9.5 Denial of Service via Unbounded CrawlerRunConfig Delay Fields
Crawl4AI before 0.9.5 contains a denial of service vulnerability in the Docker API server where clampuntrusted() fails to cap the delaybeforereturnhtml, meandelay, and maxrange fields of untrusted CrawlerRunConfig bodies. Unauthenticated attackers can send huge values to /crawl or /crawl/stream to hold browser pages or stall the rate limiter, exhausting the page pool and blocking other crawls.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Crawl4AIto a version that resolves this vulnerability.Fixed in 0.9.5
Event History
Frequently Asked Questions
Who is exposed to this issue?
Deployments running a Crawl4AI Docker API server before 0.9.5 are exposed if attackers can reach its /crawl or /crawl/stream endpoints. The affected request fields are accepted in untrusted CrawlerRunConfig bodies.
What does an attacker need to exploit it?
An attacker needs only network access to the Docker API server endpoints. No authentication or user interaction is required, and exploitation consists of sending very large values for delay_before_return_html, mean_delay, or max_range.
What is the operational impact of exploitation?
Large delay values can hold browser pages or stall the rate limiter, exhausting the page pool. This can block other crawl requests and cause denial of service.
What should be prioritized for remediation?
Upgrade Crawl4AI to version 0.9.5 or later. If upgrading cannot happen immediately, restrict network access to the Docker API server so untrusted clients cannot submit requests to /crawl or /crawl/stream.