Executive brief
OpenClaw is a JavaScript browser library used to enforce network policies in web applications. A vulnerability in its hostname validation allows attackers to bypass security restrictions through DNS rebinding techniques, potentially enabling unauthorized access to internal resources that should be blocked.
Technical details
This is a server-side request forgery (SSRF) vulnerability in OpenClaw's browser navigation policy enforcement. The root cause is a time-of-check-time-of-use (TOCTOU) race condition where hostname validation occurs at one point in time, but the actual network request uses a different DNS resolution result obtained later through DNS rebinding. An attacker can craft a malicious URL that passes initial hostname validation but resolves to an internal IP address when the browser actually makes the request, allowing navigation to unallowlisted hosts. The vulnerability requires network access and affects versions before 2026.4.10, which was patched to fail closed on restrictive policy enforcement. The fix is available in openclaw 2026.4.10 and later versions.
Affected products
- OpenClaw openclaw before 2026.4.10
Timeline
- 2026-04-16: disclosed
- 2026-04-16: patched: Fixed in version 2026.4.10