Moderate Security Update for Python Packages in AlmaLinux: Addressing DoS Vulnerabilities
Summary
ALSA-2026:1828: Moderate: python3.12 security update. Affects python-unversioned-command versions < 3.12.12-3.el10_1. Fixed in 3.12.12-3.el10_1. How to fix ↓
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Background
Python is a versatile, interpreted programming language known for its object-oriented features, dynamic typing, and extensive libraries. It supports various system calls and interfaces, making it a popular choice for developers. However, recent vulnerabilities have been identified in Python 3.12, specifically affecting several packages within the AlmaLinux ecosystem, such as python3, python3-devel, and python3-libs. These vulnerabilities could lead to denial of service (DoS) attacks, impacting the performance and availability of applications relying on these packages.
Vulnerability Detail
The vulnerabilities stem from two main issues: an excessive read buffering DoS in the http.client module (CVE-2025-13836) and a quadratic algorithm in xml.dom.minidom that can also lead to denial of service (CVE-2025-12084). These vulnerabilities can be exploited by attackers to consume excessive resources, potentially crashing the application or making it unresponsive. The technical implications include the possibility of an attacker sending crafted requests that trigger the excessive buffering or exploiting the inefficient algorithm, leading to performance degradation.
How To Fix
Minimum fixed version
3.12.12-3.el10_1
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, you can limit the input size for the http.client module and avoid using the xml.dom.minidom for parsing XML data until the packages are updated. This can help mitigate the risk of exploitation until a proper fix is applied.
Conclusion
In summary, the recent vulnerabilities in Python 3.12 pose a moderate risk to applications running on AlmaLinux. It is crucial to update the affected packages to the patched version to mitigate the risk of denial of service attacks. Utilizing tools like Vulert can further enhance your security posture by monitoring for vulnerabilities in real-time.
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FAQ
The main vulnerabilities include excessive read buffering in http.client and a quadratic algorithm in xml.dom.minidom, both of which can lead to denial of service.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by these vulnerabilities without needing to sign up.
If immediate updates are not possible, consider implementing input size limits and avoiding vulnerable modules as temporary workarounds.
While specific exploits may not be publicly available, the vulnerabilities are known to be exploitable, and it is advisable to apply updates promptly.
Vulert is a tool that monitors and alerts for open-source vulnerabilities in your software using a manifest file like package-lock.json. It helps ensure your applications remain secure.
Related vulnerabilities
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