Moderate Vulnerability in Python 3.9: Denial of Service Risk via xml.dom.minidom
Summary
ALSA-2026:1478: Moderate: python3.9 security update. Affects python-unversioned-command versions < 3.9.25-3.el9_7. Fixed in 3.9.25-3.el9_7. How to fix ↓
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Background
Python is a widely-used interpreted, interactive, object-oriented programming language known for its simplicity and versatility. It supports various system calls and libraries, making it a popular choice for developers. The affected package, Python 3.9, includes features such as modules, classes, and dynamic typing, but it has been identified to have a security flaw in the xml.dom.minidom module that can lead to a denial of service.
Vulnerability Detail
The vulnerability arises from a quadratic algorithm in the xml.dom.minidom module of Python 3.9, which can be exploited to cause a denial of service. This means that an attacker could craft specific XML input that, when processed, would significantly degrade the performance of the application or even crash it. The issue is tracked under CVE-2025-12084, highlighting its potential impact on applications relying on this module for XML processing.
How To Fix
Minimum fixed version
3.9.25-3.el9_7
This is the first release that contains the fix.
sudo dnf update python-unversioned-commandTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, avoid processing untrusted XML input or limit the size and complexity of XML documents being processed by your application until the update can be applied.
Conclusion
In summary, the identified vulnerability in Python 3.9 poses a moderate risk of denial of service due to a flaw in the xml.dom.minidom module. It is crucial to update the affected packages to the patched version to ensure the security and stability of your applications. Utilizing tools like Vulert can help in monitoring and managing vulnerabilities effectively.
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FAQ
The vulnerability is a denial of service risk caused by a quadratic algorithm in the xml.dom.minidom module of Python 3.9.
You can check if your application is affected by using Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to use the Vulert playground without signup.
If left unaddressed, the vulnerability could allow attackers to exploit your application, leading to performance degradation or crashes.
Yes, you should update to version 3.9.25-3.el9_7 or later to mitigate the vulnerability.
Yes, Vulert can monitor various open-source vulnerabilities in your software using just a manifest file like package-lock.json.
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