Openclaw cli: OpenClaw Twilio voice-call webhook auth bypass when ngrok loopback compatibility is enabled (CVE-2026-29606)

CVE-2026-29606 describes a Twilio webhook signature verification bypass in the OpenClaw CLI voice-call extension. This bypass occurs only when the 'tunnel.allowNgrokFreeTierLoopbackBypass' option is enabled, allowing unauthenticated webhook requests to be accepted if the webhook endpoint is publicly exposed, such as through a public ngrok URL. The vulnerability could allow attackers to send forged requests that bypass the 'X-Twilio-Signature' verification, leading to unauthorized webhook event processing and potential denial of service via request flooding. The vulnerability affects versions >=2026.1.29 and <2026.2.14 of the openclaw package. The fix, included in version 2026.2.14, removes the bypass and ensures signature verification is properly enforced while still supporting trusted forwarded headers for loopback compatibility.

The impact is limited to configurations where the voice-call webhook extension is enabled and exposed publicly with the 'tunnel.allowNgrokFreeTierLoopbackBypass' option enabled. In such cases, an attacker can send unauthenticated webhook requests that bypass Twilio's signature verification, potentially causing unauthorized webhook event handling (integrity impact) and request flooding (availability impact). By default, the voice-call extension is disabled and the bypass does not apply, reducing the risk in typical deployments.

A patch is available in openclaw version 2026.2.14 that removes the signature verification bypass while maintaining trusted forwarded header support. Users should upgrade to version 2026.2.14 or later. If upgrading immediately is not possible, ensure that the voice-call extension is disabled or that the 'tunnel.allowNgrokFreeTierLoopbackBypass' option is not enabled. Avoid exposing the webhook endpoint publicly without proper signature verification.