Critical Security Update for python3-lxml: Addressing URL Bypass Vulnerability
Summary
ALSA-2026:66204: Important: python-lxml security update. Affects python3-lxml versions < 4.6.5-3.el9_8.1. Fixed in 4.6.5-3.el9_8.1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
Python3-lxml is a powerful library for processing XML and HTML in Python. It provides a rich set of features for parsing, creating, and manipulating XML and HTML documents. The library is widely used in web scraping, data processing, and web application development due to its ease of use and performance. However, it has been found to have a security vulnerability that could potentially allow attackers to bypass URL restrictions, leading to unauthorized access to resources.
Vulnerability Detail
The vulnerability identified as CVE-2026-49825 is a URL bypass issue in the lxml-html-clean module of the python3-lxml package. This flaw arises from a missing xlink:href attribute in the Cleaner component, which can be exploited by attackers to manipulate URLs and access restricted resources. The ramifications of this vulnerability can include unauthorized data access, data leakage, and potential exploitation of the application using the library.
How To Fix
Minimum fixed version
4.6.5-3.el9_8.1
This is the first release that contains the fix.
sudo dnf update python3-lxmlTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, you can implement input validation to sanitize URLs before processing them with the Cleaner component. This can help mitigate the risk of exploitation until the package is updated.
Conclusion
The python3-lxml package has a critical vulnerability that needs immediate attention. By updating to the latest patched version, users can protect their applications from potential exploitation. It is also advisable to implement workarounds to minimize risks while waiting for updates.
See every vulnerability recorded for python3-lxml →
FAQ
CVE-2026-49825 is a security vulnerability in the python3-lxml package that allows for URL bypass due to a missing xlink:href attribute.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
The potential impacts include unauthorized access to resources, data leakage, and exploitation of applications that rely on the affected library.
You can update the package by running 'sudo dnf update python3-lxml' in your terminal to install the patched version.
Yes, implementing input validation to sanitize URLs can help mitigate the risk until the package is updated.
Related vulnerabilities
Recent vulnerabilities recorded for python3-lxml.
