Compliance Impact

The provided information does not explicitly address how CVE-2026-41405 affects compliance with common standards and regulations such as GDPR or HIPAA.

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Executive Summary

CVE-2026-41405 is a vulnerability in OpenClaw versions before 2026.3.31 where the system parses Microsoft Teams webhook request bodies before validating the JWT (JSON Web Token) authentication. This improper sequence allows unauthenticated attackers to send malicious webhook payloads that are parsed before authentication, leading to resource exhaustion on the server.

The core issue is that the JSON body parser runs before the JWT validation middleware, so attackers can exploit this by sending large or crafted payloads that consume excessive CPU and memory resources, potentially causing denial-of-service.

The vulnerability was fixed by changing the middleware order to validate JWT tokens before parsing the JSON body, preventing unauthenticated requests from consuming server resources.

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Impact Analysis

This vulnerability can impact you by allowing remote unauthenticated attackers to exhaust your server's resources through malicious Microsoft Teams webhook payloads.

Because the system parses the request body before authentication, attackers can send large or specially crafted payloads that consume excessive CPU and memory, leading to denial-of-service conditions.

Such resource exhaustion can degrade system performance, cause service outages, and disrupt normal operations, potentially affecting availability and reliability of your services.

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Detection Guidance

This vulnerability can be detected by monitoring incoming Microsoft Teams webhook requests to the OpenClaw server and checking whether JWT authentication is performed before parsing the JSON payload. Specifically, if the system parses webhook request bodies before validating JWT tokens, it is vulnerable.

To detect exploitation attempts, you can look for unusually large or malformed webhook payloads arriving without valid JWT authentication headers.

Since the vulnerability involves the order of middleware processing in the OpenClaw application, direct detection on the network level may be limited. However, you can use logging or debugging on the server to verify if JWT validation occurs before JSON parsing.

Suggested commands to check for suspicious requests or test the vulnerability might include using curl to send a Teams webhook payload without a valid JWT token and observing server behavior or logs. For example:

• curl -X POST https://your-openclaw-server/webhook-endpoint -H "Content-Type: application/json" -d '{"text":"test"}'
• curl -X POST https://your-openclaw-server/webhook-endpoint -H "Content-Type: application/json" -H "Authorization: Bearer invalidtoken" -d '{"text":"test"}'

Monitoring server logs for resource exhaustion or errors related to JSON parsing on unauthenticated requests can also help detect attempts to exploit this vulnerability.

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Mitigation Strategies

The primary mitigation step is to upgrade OpenClaw to version 2026.3.31 or later, where the vulnerability has been fixed by reordering middleware to perform JWT authentication before parsing the JSON body of Microsoft Teams webhook requests.

If upgrading immediately is not possible, consider implementing a temporary workaround by configuring the webhook endpoint to reject requests without valid JWT tokens before processing the request body.

Additionally, monitor and limit the size of incoming webhook payloads to reduce the risk of resource exhaustion.

Review server logs for suspicious activity and consider applying rate limiting or firewall rules to restrict unauthenticated or malformed webhook requests.

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