CVE-2026-39313: Quantgeekdev Mcp-Framework

High severity, CVSS 8.7. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Quantgeekdev Mcp-Framework: before 0.2.22 (fixed in 0.2.22)

Published 2026-04-16. Last modified 2026-06-17.