Critical Security Update for mingw-expat: Mitigating Memory Allocation Vulnerability
Summary
ALSA-2025:21974: Important: mingw-expat security update. Affects mingw32-expat versions < 2.5.0-1.el8_10. Fixed in 2.5.0-1.el8_10. How to fix ↓
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Background
Expat is a widely used C library designed for parsing XML documents efficiently. The mingw-expat packages provide a MinGW-compatible version of this library, enabling developers to utilize Expat's capabilities in Windows environments. However, the library has recently been identified as vulnerable to a security issue that allows attackers to exploit memory allocation processes, potentially leading to denial of service or other malicious activities.
Vulnerability Detail
The vulnerability, identified as CVE-2025-59375, stems from the libexpat component of the Expat library. It allows attackers to trigger large dynamic memory allocations by submitting a small XML document for parsing. This can lead to excessive memory consumption, resulting in application crashes or denial of service. The issue is particularly concerning as it can be exploited with minimal input, making it a low-barrier attack vector for malicious actors.
How To Fix
Minimum fixed version
2.5.0-1.el8_10
This is the first release that contains the fix.
sudo dnf update mingw32-expatTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, users can avoid processing untrusted XML documents or limit the size of XML inputs to mitigate the risk of exploitation until the package is updated.
Conclusion
The mingw-expat library has a critical vulnerability that can be exploited through memory allocation issues. It is crucial for users to update to the latest patched version to ensure the security and stability of their applications. Utilizing tools like Vulert can help monitor and alert for such vulnerabilities in real-time.
See every vulnerability recorded for mingw32-expat →
FAQ
CVE-2025-59375 is a vulnerability in the Expat library that allows attackers to exploit memory allocation processes through small XML documents.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
Exploitation of this vulnerability can lead to excessive memory consumption, application crashes, or denial of service, affecting the stability of applications using the Expat library.
Yes, a patch is available in version 2.5.0-1.el8_10 of the mingw32-expat and mingw64-expat packages.
If immediate updates are not possible, avoid processing untrusted XML documents or limit the size of XML inputs as a temporary workaround.
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