mcp-framework — Dos (CVE-2026-39313)
Date: 2026-04
Attack vector: dos
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-39313
CWE: CWE-770

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.


Mitigations:

Architectural layers (MAESTRO):