CVE-2026-39313

MCP-Framework: Unbounded memory allocation in readRequestBody allows denial of service via HTTP transport

Published Apr 16, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-353c-v8x9-v7c3 MCP-Framework: Unbounded memory allocation in readRequestBody allows denial of service via HTTP transport
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Quantgeekdev
Quantgeekdev mcp-framework
Vendors & Products Quantgeekdev
Quantgeekdev mcp-framework
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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Apr 17, 2026, 6:46 PM
Reserved
Apr 6, 2026, 7:31 PM
Status
Deferred
Published
Apr 16, 2026, 10:16 PM
Modified
Oct 26, 2026, 9:10 PM