What’s Vulnerable › Vulnerabilities

CVE-2026-39313: MCP-Framework: Unbounded memory allocation in readRequestBody allows denial of service via HTTP transport

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-16 · updated 2026-10-26
• Weakness: CWE-770

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.

Affected products

• QuantGeekDev mcp-framework: before 0.2.22

References

• https://github.com/QuantGeekDev/mcp-framework/commit/f97d2bb76d6359faf10cd1fc54b4911476b62524
• https://github.com/QuantGeekDev/mcp-framework/security/advisories/GHSA-353c-v8x9-v7c3

Get alerted when CVE-2026-39313 or the next vulnerability affects your stack