Is CVE-2026-39313 actively exploited?

CVE-2026-39313 has no public evidence of in-the-wild exploitation as of 2026-04-17.

What is the CVSS score for CVE-2026-39313?

CVE-2026-39313 has a CVSS score of 8.7 (HIGH severity). 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

How do I patch CVE-2026-39313?

Vendor patch guidance is linked from the references on this page. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-39313.

Which products are affected by CVE-2026-39313?

Affected products for CVE-2026-39313 are listed on this page once vendor data becomes available.

Fix CVE-2026-39313 - HIGH Vulnerability

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.

CVSS Metrics

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-770

Metadata

Primary Vendor: UNKNOWN
Published: 4/16/2026
Last Modified: 4/17/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2026-39313

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary