VULNERABILITY INTELLIGENCE
CVE-2026-39313
EPSS probability0.50%
CISA KEVNot currently listed
Published2026-04-16
Last modified2026-10-26
Description
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.
Weakness classification
- security-advisories@github.com: CWE-770