Critical Vulnerability in libxml2: Heap Use After Free and Integer Overflow Issues
Summary
RLSA-2025:10699: Important: libxml2 security update. Affects libxml2 versions < 0:2.9.13-10.el9_6. Fixed in 0:2.9.13-10.el9_6. How to fix ↓
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Background
libxml2 is a widely-used development toolbox that provides the implementation of various XML standards. It is essential for applications that require XML parsing and manipulation. The library is known for its performance and flexibility, making it a popular choice among developers. However, recent vulnerabilities have raised concerns about its security, particularly in the context of Denial of Service (DoS) attacks and potential buffer overflows.
Vulnerability Detail
The vulnerabilities in libxml2 stem from a heap use after free (UAF) condition, type confusion, and an integer overflow in the xmlBuildQName() function. These issues can lead to Denial of Service (DoS) attacks, where an attacker can exploit these vulnerabilities to crash applications that rely on libxml2 for XML processing. The vulnerabilities are identified as CVE-2025-49794, CVE-2025-49796, and CVE-2025-6021, with a CVSS score of 9.1, indicating a critical severity level.
How To Fix
Minimum fixed version
0:2.9.13-10.el9_6
This is the first release that contains the fix.
sudo dnf update libxml2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider limiting the use of libxml2 in critical applications until the package can be updated. Additionally, review your application code to ensure that it handles XML data safely and does not expose itself to potential attacks.
Conclusion
The vulnerabilities in libxml2 pose significant risks to applications that rely on this library for XML processing. It is crucial to update to the patched version to mitigate these risks and ensure the security of your applications. Regular monitoring for vulnerabilities using tools like Vulert can help maintain a secure software environment.
See every vulnerability recorded for libxml2 →
FAQ
libxml2 is a development library used for parsing and manipulating XML data in applications.
The main vulnerabilities include heap use after free, type confusion, and integer overflow, which can lead to Denial of Service attacks.
You can use the Vulert platform to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected.
The vulnerabilities have a CVSS score of 9.1, indicating a critical severity level.
You can update libxml2 by running the command 'sudo dnf update libxml2' in your terminal.
References
Related vulnerabilities
Recent vulnerabilities recorded for libxml2.
