Uncaught exception in MCP Python SDK - CVE-2025-53366
Published: December 18, 2025
Vulnerability identifier: #VU120187
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2025-53366
CWE-ID: CWE-248
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to an unhandled exception when processing malformed requests. A remote attacker can send specially crafted requests to the application and perform a denial of service attack.
Affected software
MCP Python SDK
openEuler
python-mcp
python3-mcp
openEuler
python-mcp
python3-mcp
How to mitigate CVE-2025-53366
Install updates from vendor's website.
MCP Python SDK - update to 1.9.4
python-mcp - update to 1.12.3-1
python3-mcp - update to 1.12.3-1
python-mcp - update to 1.12.3-1
python3-mcp - update to 1.12.3-1