High severity · published Apr 16, 2026
CVE-2026-39313
MCP-Framework: Unbounded memory allocation in readRequestBody allows denial of service via HTTP transport
8.7
CVSS
0.5%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
mcp-framework · QuantGeekDev
< 0.2.22 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39313
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-39313
github.com
https://github.com/QuantGeekDev/mcp-framework/commit/f97d2bb76d6359faf10cd1fc54b4911476b62524
github.com
https://github.com/QuantGeekDev/mcp-framework/security/advisories/GHSA-353c-v8x9-v7c3
