QuantGeekDev mcp-framework up to 0.2.21 Model Context Protocol /mcp readRequestBody maxMessageSize allocation of resources

Summaryinfo

A vulnerability was found in QuantGeekDev mcp-framework up to 0.2.21. It has been declared as problematic. Affected is the function readRequestBody of the file /mcp of the component Model Context Protocol. The manipulation of the argument maxMessageSize results in allocation of resources. This vulnerability is reported as CVE-2026-39313. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in QuantGeekDev mcp-framework up to 0.2.21. It has been classified as problematic. Affected is the function readRequestBody of the file /mcp of the component Model Context Protocol. The manipulation of the argument maxMessageSize with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on availability. CVE summarizes:

mcp-framework is a framework for building Model Context Protocol (MCP) servers. In versions 0.2.21 and below, the readRequestBody() function in the HTTP transport concatenates request body chunks into a string with no size limit. Although a maxMessageSize configuration value exists, it is never enforced in readRequestBody(). A remote unauthenticated attacker can crash any mcp-framework HTTP server by sending a single large POST request to /mcp, causing memory exhaustion and denial of service. This issue has been fixed in version 0.2.22.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-39313 since 04/06/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 0.2.22 eliminates this vulnerability. Applying the patch f97d2bb76d6359faf10cd1fc54b4911476b62524 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Artificial Intelligence Software

Vendor

• QuantGeekDev

Name

• mcp-framework

Version

• 0.2.0
• 0.2.1
• 0.2.2
• 0.2.3
• 0.2.4
• 0.2.5
• 0.2.6
• 0.2.7
• 0.2.8
• 0.2.9
• 0.2.10
• 0.2.11
• 0.2.12
• 0.2.13
• 0.2.14
• 0.2.15
• 0.2.16
• 0.2.17
• 0.2.18
• 0.2.19
• 0.2.20
• 0.2.21

License

• open-source

Website

• Product: https://github.com/QuantGeekDev/mcp-framework/

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