CVE-2026-39313Public exploitNetwork attack vector

Unauthenticated server crash via unbounded request body

Published Apr 16, 2026 · Updated Apr 16, 2026

Denial of service in QuantGeekDev MCP Framework 0.2.21 and earlier allows remote attackers to crash HTTP servers with a large POST request. HttpStreamTransport.readRequestBody concatenates every request chunk into a string without enforcing the configured maxMessageSize limit. The /mcp handler reaches this code before optional authentication, so one unauthenticated request can exhaust process memory and stop the service.

CVSS severity8.7
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in QuantGeekDev MCP Framework 0.2.21 and earlier allows remote attackers to crash HTTP servers with a large POST request. HttpStreamTransport.readRequestBody concatenates every request chunk into a string without enforcing the configured maxMessageSize limit. The /mcp handler reaches this code before optional authentication, so one unauthenticated request can exhaust process memory and stop the service.

The record

CVE
CVE-2026-39313
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
QuantGeekDev
Product
MCP Framework
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.2.22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

QuantGeekDev · MCP Frameworkversion=< 0.2.22

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5QuantGeekDevCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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