Critical Security Update for Python3 Packages: CPU Denial of Service Vulnerability

platform-python Updated 15 Jul 2026

Summary

14/07/2026

Disclosed on

N/A

Severity

Yes i

Fix available

Unrated

Severity

Not published

CVSS Score

ALSA-2026:39320: Important: python3 security update. Affects platform-python versions < 3.6.8-77.el8_10.alma.1. Fixed in 3.6.8-77.el8_10.alma.1. How to fix ↓

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Background

Python is a widely-used interpreted, interactive programming language known for its versatility and ease of use. It supports various programming paradigms and is equipped with extensive libraries and frameworks. The affected packages, including platform-python, python3-libs, and others, are integral to the AlmaLinux ecosystem, providing essential functionalities for application development and execution. The recent vulnerability poses a significant risk to systems utilizing these packages, potentially leading to service disruptions.

Vulnerability Detail

The vulnerability identified as CVE-2026-15308 is a CPU Denial of Service (DoS) issue in the HTML parser of Python. It arises from the handling of repeated unterminated markup declarations, which can lead to excessive CPU consumption when processing maliciously crafted HTML content. This can result in degraded performance or complete unavailability of services relying on the affected Python packages, making it critical for users to address this issue promptly.

How To Fix

Minimum fixed version

3.6.8-77.el8_10.alma.1

This is the first release that contains the fix.

sudo dnf update platform-python

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Workaround

As a temporary measure, users can limit the input to the HTML parser or implement additional validation checks to prevent the processing of potentially harmful HTML content until the package is updated.

Conclusion

The identified vulnerability in Python packages poses a significant risk to systems using AlmaLinux. It is crucial for users to update their packages to the latest patched version to mitigate potential service disruptions. Implementing temporary workarounds can provide additional protection until the update is applied.

See every vulnerability recorded for platform-python →