SB2025120606 - Denial of service in Python
Published: December 6, 2025
Security Bulletin ID
SB2025120606
Severity
Low
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 security vulnerability.
1) Inefficient algorithmic complexity (CVE-ID: CVE-2025-12084)
The vulnerability allows a remote attacker to perform a denial of service attack.
The vulnerability exists due to usage of a quadratic algorithm when building nested elements using xml.dom.minidom methods such as appendChild() that have a dependency on _clear_id_cache(). A remote attacker can force the application to create excessively nested documents, leading to a denial of service condition.
Remediation
Install update from vendor's website.
References
- https://github.com/python/cpython/commit/027f21e417b26eed4505ac2db101a4352b7c51a0
- https://github.com/python/cpython/commit/08d8e18ad81cd45bc4a27d6da478b51ea49486e4
- https://github.com/python/cpython/commit/ddcd2acd85d891a53e281c773b3093f9db953964
- https://github.com/python/cpython/issues/142145
- https://github.com/python/cpython/pull/142146