A Twilio webhook signature-verification bypass in the voice-call extension could allow unauthenticated webhook requests when a specific ngrok free-tier compatibility option is enabled.
This issue is limited to configurations that explicitly enable and expose the voice-call webhook endpoint.
Not affected by default:
tunnel.allowNgrokFreeTierLoopbackBypass was explicitly enabled.Worst case (when exposed and the option was enabled):
X-Twilio-Signature.openclaw (npm)<= 2026.2.13 (latest published as of 2026-02-14)>= 2026.2.14 (planned next release; pending publish)allowNgrokFreeTierLoopbackBypass no longer bypasses signature verification. It only enables trusting forwarded headers on loopback so the public ngrok URL can be reconstructed for correct signature validation.
Fix commit(s):
Thanks @p80n-sec for reporting.
{
"cwe_ids": [
"CWE-306"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-18T00:54:48Z",
"nvd_published_at": "2026-03-05T22:16:23Z",
"severity": "MODERATE"
}