Executive Summary

CVE-2026-34505 is a security vulnerability in OpenClaw versions prior to 2026.3.12 related to webhook rate limiting.

The issue occurs because OpenClaw only enforces rate limiting after a webhook request has been successfully authenticated.

This means attackers can repeatedly submit authentication requests with invalid webhook secrets without triggering any rate limiting.

As a result, attackers can perform brute-force attacks to systematically guess webhook secrets and potentially submit forged webhook requests.

The vulnerability is classified under CWE-307, which involves improper restriction of excessive authentication attempts.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability allows attackers to bypass rate limits and repeatedly guess webhook secrets without restriction.

If an attacker successfully guesses a webhook secret, they can submit forged webhook traffic, potentially leading to unauthorized actions or data manipulation.

The impact includes potential compromise of confidentiality and integrity of webhook communications.

Because no privileges or user interaction are required, the attack can be performed remotely and easily.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by monitoring for repeated webhook authentication requests with invalid secrets that do not trigger rate limiting responses. Specifically, look for numerous HTTP 401 Unauthorized responses without corresponding HTTP 429 Too Many Requests responses, which indicates that rate limiting is not applied before authentication.

You can use network monitoring or log analysis tools to identify such patterns. For example, using command-line tools like curl or wget to simulate repeated webhook requests with invalid secrets and observing the server responses can help verify if rate limiting is applied pre-authentication.

• Use curl to send repeated webhook requests with invalid secrets and check if HTTP 429 responses are returned:
• curl -X POST https://your-openclaw-webhook-endpoint -H 'X-Webhook-Secret: invalidsecret' -d '{}'
• Monitor server logs or use tools like tcpdump or Wireshark to detect a high volume of 401 Unauthorized responses without rate limiting.

Useful 0 Not Useful 0

Mitigation Strategies

The immediate and recommended mitigation is to update OpenClaw to version 2026.3.12 or later, where the vulnerability is fixed by applying rate limiting before webhook authentication.

Additionally, ensure that webhook secrets are strong and comply with security best practices to reduce the risk of brute-force guessing.

Useful 0 Not Useful 0

Compliance Impact

CVE-2026-34505 allows attackers to bypass rate limiting and brute-force webhook secrets, potentially leading to unauthorized access and forged webhook submissions. Such unauthorized access and data integrity issues could impact compliance with standards and regulations like GDPR and HIPAA, which require protection of sensitive data and prevention of unauthorized access.

Because the vulnerability enables systematic guessing of secrets and possible forged data submissions, it may increase the risk of data breaches or unauthorized data manipulation, which are critical concerns under these regulations.

Mitigating this vulnerability by updating to OpenClaw version 2026.3.12 or later and enforcing strong webhook secrets is important to maintain compliance with such security and privacy requirements.

Useful 0 Not Useful 0