CVE-2026-56264
CVE-2026-56264 is a Code Injection vulnerability in crawl4ai. O3 Security confirms whether CVE-2026-56264 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Crawl4AI - Arbitrary JavaScript Execution via /execute_js Endpoint
Real-World Exposure
crawl4aiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Crawl4AI before 0.8.7 contains an arbitrary JavaScript execution vulnerability in the Docker API server's /execute_js endpoint, which accepts and executes arbitrary user-supplied JavaScript in the server's browser context with --disable-web-security enabled. An attacker can execute arbitrary JavaScript and, combined with the browser's relaxed security settings, perform server-side request forgery against internal services.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | crawl4ai | all versions | 0.8.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crawl4ai. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update crawl4ai to 0.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-56264 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-56264 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-56264. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-56264 in your dependencies?
O3 detects CVE-2026-56264 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.