Use-After-Free Vulnerability in libxml2: Risk of Crashes and Undefined Behavior
Summary
DEBIAN-CVE-2025-49794: A use-after-free vulnerability was found in libxml2. Affects libxml2 versions < 2.9.10+dfsg-6.7+deb11u8. Fixed in 2.9.10+dfsg-6.7+deb11u8. 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
libxml2 is a widely used XML parsing library that provides a range of functionalities for processing XML documents. It is integral to many applications that require XML manipulation, offering features such as validation, XPath support, and document traversal. However, it is susceptible to certain vulnerabilities, including a recently identified use-after-free issue that can lead to crashes or unpredictable behavior when processing specific XML structures.
Vulnerability Detail
A use-after-free vulnerability was discovered in libxml2, which occurs during the parsing of XPath elements under specific conditions involving XML schematron schema elements. This flaw can be exploited by a malicious actor who crafts a specially designed XML document, potentially leading to application crashes or other undefined behaviors when the affected libxml2 library processes the input.
How To Fix
Minimum fixed version
2.9.10+dfsg-6.7+deb11u8
This is the first release that contains the fix.
sudo apt-get install --only-upgrade libxml2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users should avoid processing untrusted XML documents that may contain XPath elements with <sch:name path="..."/> schema elements until the library is updated.
Conclusion
The identified use-after-free vulnerability in libxml2 poses significant risks to applications relying on this library for XML processing. It is crucial for users to update to the latest patched versions to mitigate these risks and ensure the stability and security of their applications.
See every vulnerability recorded for libxml2 →
FAQ
A use-after-free vulnerability occurs when a program continues to use a memory reference after it has been freed, potentially leading to crashes or exploitation.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which allows you to monitor for open-source vulnerabilities without any signup.
The risks include application crashes and potential exploitation by attackers, leading to unauthorized access or data corruption.
Yes, avoid processing untrusted XML documents that may exploit this vulnerability until the library is updated.
More information about libxml2 can be found on its official website or documentation, which provides insights into its features and usage.
References
Related vulnerabilities
Recent vulnerabilities recorded for libxml2.
