Denial of Service Vulnerability in OpenClaw: Unauthenticated Request Body Parsing

openclaw Updated 10 Apr 2026

Summary

10/04/2026

Disclosed on

MODERATE

Severity

Yes i

Fix available

Moderate

Severity

5.3

CVSS Score

GHSA-8f9r-gr6r-x63q: Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-3h52-cx59-c456. Affects openclaw versions < 2026.3.28. Fixed in 2026.3.28. How to fix ↓

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Background

OpenClaw is an open-source package designed for integrating with various webhooks, enabling applications to receive real-time updates and notifications. It is commonly used in environments that require automated responses to events. However, prior to version 2026.3.28, OpenClaw had a critical vulnerability that allowed unauthenticated attackers to exploit its JSON parsing capabilities, leading to potential denial of service (DoS) attacks.

Vulnerability Detail

The vulnerability arises from OpenClaw's handling of JSON request bodies before validating webhook signatures. This flaw allows attackers to send crafted requests that force the server to perform resource-intensive parsing operations. As a result, the server may become overwhelmed, leading to service unavailability. The vulnerability is classified under CWE-696, indicating improper handling of input data, and has a CVSS score of 5.3, indicating a moderate severity level.

How To Fix

Latest published version: 2026.10.6 as of 22 Oct 2026

npm install openclaw@2026.10.6

Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.

If you need the minimum change

2026.3.28

This is the first release that contains the fix.

npm install openclaw@2026.3.28

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Workaround

As a temporary measure, you can implement input validation to reject any requests that do not have valid signatures before processing the JSON body. This can be done by adding a middleware function in your application that checks the signature before allowing further processing of the request.

Conclusion

In summary, the vulnerability in OpenClaw allows unauthenticated attackers to exploit JSON parsing, leading to potential denial of service. It is crucial to update to version 2026.3.28 or later to mitigate this risk. Implementing input validation can serve as a temporary workaround while you plan for the update.

See every vulnerability recorded for openclaw →