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.
History

Thu, 16 Apr 2026 21:30:00 +0000

Type Values Removed Values Added
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.
Title MCP-Framework: Unbounded memory allocation in readRequestBody allows denial of service via HTTP transport
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-04-16T21:24:27.328Z

Updated: 2026-04-16T21:24:27.328Z

Reserved: 2026-04-06T19:31:07.265Z

Link: CVE-2026-39313

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-16T22:16:38.073

Modified: 2026-04-16T22:16:38.073

Link: CVE-2026-39313

cve-icon Redhat

No data.