CVE-2026-39313

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.

Score

CVSS 4.0 8.7 High

Status

Deferred - security-advisories@github.com

Published

2026-04-16

Last modified

2026-10-26

Weaknesses

CWE-770

Affected products

• Mcp-framework (Quantgeekdev)

References

• https://github.com/QuantGeekDev/mcp-framework/security/advisories/GHSA-353c-v8x9-v7c3
• https://github.com/QuantGeekDev/mcp-framework/commit/f97d2bb76d6359faf10cd1fc54b4911476b62524