CVE-2026-26319: Openclaw Authentication Bypass Vulnerability

CVE-2026-26319 Overview

CVE-2026-26319 is an authentication bypass vulnerability in OpenClaw, a personal AI assistant application. The flaw affects the optional @openclaw/voice-call plugin in versions 2026.2.13 and earlier. When the telnyx.publicKey value is not configured, the Telnyx webhook handler accepts unsigned inbound webhook requests. This fail-open condition lets unauthenticated attackers forge Telnyx events by sending arbitrary HTTP POST requests to the voice-call webhook endpoint. The vulnerability is tracked as [CWE-306: Missing Authentication for Critical Function]. OpenClaw fixed the issue in version 2026.2.14.

Critical Impact
Unauthenticated network attackers can forge Telnyx voice-call events against vulnerable OpenClaw deployments, compromising the integrity of webhook-driven workflows when the plugin is publicly reachable.

Affected Products

OpenClaw versions 2026.2.13 and below (Node.js distribution)
Deployments with the @openclaw/voice-call plugin installed and enabled
Instances where the webhook endpoint is reachable from the internet via tunnel or proxy

Discovery Timeline

2026-02-19 - CVE-2026-26319 published to NVD
2026-02-20 - Last updated in NVD database

Technical Details for CVE-2026-26319

Vulnerability Analysis

The vulnerability resides in the TelnyxProvider.verifyWebhook() function within the OpenClaw voice-call plugin. Telnyx webhooks are designed to be authenticated using Ed25519 signature verification. The verification routine requires a configured telnyx.publicKey value to validate inbound webhook signatures. When the public key is absent, the function fails open rather than rejecting the request. This design defect allows any HTTP POST request reaching the webhook endpoint to be processed as a legitimate Telnyx event. The flaw breaks the integrity guarantee of the voice-call event pipeline and exposes downstream call-handling logic to attacker-controlled data.

Root Cause

The root cause is missing authentication for a critical function ([CWE-306]). The verifyWebhook() implementation treated an unconfigured public key as a permissive state instead of a hard failure. Secure webhook handlers must reject all requests when signature verification material is unavailable. The vendor's fix enforces a closed-by-default posture so that absent or invalid signing keys cause webhook requests to be rejected.

Attack Vector

An attacker only needs network access to the webhook endpoint. No credentials, user interaction, or prior privileges are required. The attacker sends a crafted HTTP POST request mimicking a Telnyx event payload to the voice-call webhook URL. If the deployment has not configured telnyx.publicKey, OpenClaw processes the forged event as authentic. This impacts the integrity of voice-call state and any business logic, automations, or AI assistant actions triggered by Telnyx events.

No verified public exploit code is currently available. See the GitHub Security Advisory GHSA-4hg8-92x6-h2f3 for additional context.

Detection Methods for CVE-2026-26319

Indicators of Compromise

Inbound HTTP POST requests to the voice-call webhook endpoint missing the expected Telnyx-Signature-Ed25519 header or carrying invalid signatures.
Telnyx event records in OpenClaw logs that do not correspond to any outbound Telnyx API activity or active call session.
Unexpected state transitions in voice-call sessions originating from unfamiliar source IP ranges outside Telnyx-published address space.

Detection Strategies

Audit OpenClaw configuration files and environment variables for an unset or empty telnyx.publicKey value.
Inspect application logs for webhook events accepted without signature verification while running version 2026.2.13 or below.
Correlate webhook events against the Telnyx provider's outbound call records to identify forged inbound events.

Monitoring Recommendations

Enable verbose logging on the voice-call plugin's webhook handler to record signature validation outcomes per request.
Place the OpenClaw instance behind a reverse proxy that enforces IP allowlisting for Telnyx source ranges.
Alert on any HTTP POST to the voice-call webhook path from non-Telnyx address space or from unauthenticated tunneling services.

How to Mitigate CVE-2026-26319

Immediate Actions Required

Upgrade OpenClaw to version 2026.2.14 or later, which enforces strict Ed25519 signature verification.
If upgrading is not immediately possible, disable the @openclaw/voice-call plugin until the patch is applied.
Configure a valid telnyx.publicKey in all deployments before re-enabling the voice-call webhook endpoint.

Patch Information

The vendor released the fix in OpenClaw v2026.2.14. The code changes are documented in commits 29b587e and f47584f. The patched TelnyxProvider.verifyWebhook() rejects requests when no public key is configured rather than failing open.

Workarounds

Remove or disable the optional @openclaw/voice-call plugin in deployments where voice calling is not required.
Restrict network access to the webhook endpoint using firewall rules or reverse-proxy allowlists limited to Telnyx-published IP ranges.
Terminate any public tunnels or proxies exposing the OpenClaw instance until signature verification is properly configured.

bash

# Configuration example: enforce Telnyx signature verification
# Set the Ed25519 public key from the Telnyx portal before enabling the plugin
export TELNYX_PUBLIC_KEY="<your-telnyx-ed25519-public-key>"

# Verify the OpenClaw installed version is patched
npm ls @openclaw/openclaw | grep -E '2026\.2\.(1[4-9]|[2-9][0-9])'