Critical Memory Corruption Vulnerability in libxml2: CVE-2025-49796
Summary
UBUNTU-CVE-2025-49796: A vulnerability was found in libxml2. Affects libxml2 versions < 2.9.1+dfsg1-3ubuntu4.13+esm8. Fixed in 2.9.1+dfsg1-3ubuntu4.13+esm8. How to fix ↓
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Background
libxml2 is a widely used XML parsing library that provides a range of functionalities for processing XML documents. It is known for its performance and compliance with XML standards, making it a critical component in many applications that require XML parsing. However, a vulnerability has been identified that can lead to memory corruption when processing specific XML elements, potentially compromising the stability and security of applications relying on this library.
Vulnerability Detail
A vulnerability was found in libxml2 that affects how certain sch:name elements are processed in input XML files. This flaw can trigger memory corruption, allowing an attacker to craft a malicious XML input file that may lead libxml2 to crash. The ramifications include denial of service and the risk of undefined behavior due to sensitive data being corrupted in memory. The CVSS score for this vulnerability is 9.1, indicating a critical severity level.
How To Fix
Minimum fixed version
2.9.1+dfsg1-3ubuntu4.13+esm8
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, avoid processing untrusted XML files or implement strict validation of XML inputs to mitigate the risk of triggering the vulnerability until the package can be updated.
Conclusion
The vulnerability CVE-2025-49796 in libxml2 poses a significant risk due to its potential for memory corruption and denial of service. It is crucial for users and developers to update to the patched version of the library and to implement best practices in XML file handling to mitigate risks.
See every vulnerability recorded for libxml2 →
FAQ
CVE-2025-49796 is a critical vulnerability in libxml2 that can lead to memory corruption when processing specific XML elements.
You can use Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected by this vulnerability.
The vulnerability can lead to denial of service and undefined behavior, potentially compromising sensitive data and application stability.
Yes, a patched version of libxml2 is available. Updating to the latest version will resolve the vulnerability.
If immediate updates are not possible, avoid processing untrusted XML files and implement strict validation of XML inputs as a temporary measure.
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