SB2025121828 - Uncaught exception in MCP Python SDK
Published: December 18, 2025
Security Bulletin ID
SB2025121828
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Uncaught exception (CVE-ID: CVE-2025-53365)
CWE-ID: CWE-248 - Uncaught Exception
CVSSv4: 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:U/U:Green
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to an unhandled exception when a client deliberately triggers an exception after establishing a streamable HTTP session. A remote attacker can crash the server.
Remediation
Install update from vendor's website.