CVE-2026-26316 Overview
CVE-2026-26316 is an authentication bypass vulnerability in OpenClaw, a personal AI assistant application. The vulnerability exists in the optional BlueBubbles iMessage channel plugin, which incorrectly accepts webhook requests as authenticated based solely on the TCP peer address being a loopback address (127.0.0.1, ::1, ::ffff:127.0.0.1), even when the configured webhook secret is missing or incorrect.
This authorization bypass (CWE-863) allows attackers to send unauthorized webhook requests to the BlueBubbles plugin when public-facing reverse proxies forward traffic to a loopback-bound Gateway without implementing strong upstream authentication. The vulnerability does not affect the default iMessage integration unless BlueBubbles is specifically installed and enabled.
Critical Impact
Attackers can bypass webhook authentication by exploiting loopback address trust, potentially allowing unauthorized access to iMessage functionality and injection of malicious webhook payloads through misconfigured reverse proxy deployments.
Affected Products
- OpenClaw versions prior to 2026.2.13
- OpenClaw deployments with BlueBubbles iMessage plugin enabled
- Systems with public-facing reverse proxies forwarding to loopback-bound Gateway
Discovery Timeline
- 2026-02-19 - CVE CVE-2026-26316 published to NVD
- 2026-02-19 - Last updated in NVD database
Technical Details for CVE-2026-26316
Vulnerability Analysis
The vulnerability stems from improper authorization (CWE-863) in the BlueBubbles iMessage channel plugin's webhook authentication logic. The plugin was designed to trust requests originating from loopback addresses without properly validating the configured webhook secret. This design assumption breaks down in modern deployment scenarios where reverse proxies are commonly used to handle external traffic.
When a reverse proxy forwards external requests to a backend service bound to localhost, the TCP peer address seen by the application becomes the loopback address. This causes the vulnerable authentication logic to incorrectly treat potentially malicious external requests as trusted internal traffic, completely bypassing the webhook secret validation.
The impact allows unauthorized parties to send arbitrary webhook requests to the BlueBubbles plugin, which could enable manipulation of iMessage functionality, injection of malicious content, or other unauthorized operations depending on the plugin's capabilities.
Root Cause
The root cause is flawed trust logic in the webhook authentication mechanism. The BlueBubbles plugin implementation trusted requests from loopback addresses unconditionally, treating source IP address as a sufficient authentication factor. This violates the principle that network-level controls should not substitute for application-level authentication, especially in environments where reverse proxies can mask the true origin of requests.
The authentication check prioritized the TCP peer address over the configured webhook secret, allowing the secret validation to be bypassed entirely when requests appeared to originate from localhost.
Attack Vector
The attack vector requires a specific deployment configuration where a public-facing reverse proxy forwards external traffic to an OpenClaw Gateway instance bound to a loopback address. In this scenario, an attacker can send crafted webhook requests through the reverse proxy.
When these requests reach the BlueBubbles plugin, the TCP peer address appears as a loopback address (from the reverse proxy), causing the authentication logic to accept the request without validating the webhook secret. This allows the attacker to interact with the BlueBubbles plugin as if they were an authenticated internal service.
The attack does not require any credentials or valid webhook secrets - the attacker simply needs network access to the public-facing reverse proxy endpoint.
Detection Methods for CVE-2026-26316
Indicators of Compromise
- Unexpected webhook requests to the BlueBubbles plugin endpoint from external sources
- Unusual iMessage-related activity originating from the OpenClaw application
- Authentication logs showing webhook requests accepted without proper secret validation
- Anomalous reverse proxy access patterns targeting the BlueBubbles webhook endpoint
Detection Strategies
- Monitor reverse proxy logs for suspicious webhook requests targeting BlueBubbles endpoints
- Implement logging for all webhook authentication decisions, including the basis for authentication acceptance
- Review OpenClaw application logs for unexpected BlueBubbles plugin activity
- Deploy network monitoring to identify unauthorized webhook traffic patterns
Monitoring Recommendations
- Enable verbose logging for the BlueBubbles plugin authentication component
- Configure alerting for webhook requests that bypass secret validation
- Monitor for configuration changes that remove or weaken webhook authentication requirements
- Track application version to ensure patched versions are deployed
How to Mitigate CVE-2026-26316
Immediate Actions Required
- Upgrade OpenClaw to version 2026.2.13 or later immediately
- Verify BlueBubbles webhook password is configured with a strong, non-empty value
- Review reverse proxy configurations for proper upstream authentication
- Audit deployments where public-facing proxies forward to loopback-bound services
Patch Information
The vulnerability has been patched in OpenClaw version 2026.2.13. The fix ensures that webhook secret validation is enforced regardless of the source IP address. Security patches are available through the following commits:
For the official release, see the GitHub Release v2026.2.13. Full details are available in the GitHub Security Advisory GHSA-pchc-86f6-8758.
Workarounds
- Set a strong, non-empty BlueBubbles webhook password in the configuration
- Implement strong upstream authentication at the reverse proxy level before forwarding to the Gateway
- Avoid deployment architectures where public-facing reverse proxies forward directly to loopback-bound services without additional authentication layers
- Consider disabling the BlueBubbles plugin if not actively required until patching can be completed
# Configuration example - ensure BlueBubbles webhook secret is properly configured
# In OpenClaw configuration file, verify the webhook password is set:
bluebubbles:
enabled: true
webhook_secret: "<strong-randomly-generated-secret>"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
