Critical Security Update for Expat Packages: CVE-2026-77214

expat Updated 10 Oct 2026

Summary

10/10/2026

Disclosed on

N/A

Severity

Yes i

Fix available

High

Severity

8.2

CVSS Score

RHSA-2026:77959: Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update. Affects expat versions < 0:2.8.5-1.2.hum1. Fixed in 0:2.8.5-1.2.hum1. How to fix ↓

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Background

Expat is an XML parser library that is widely used in various software applications for parsing XML documents. It provides a simple and efficient way to handle XML data, making it a popular choice among developers. The library is known for its speed and ease of use, but like any software, it can be vulnerable to security issues. The current vulnerability, identified as CVE-2026-77214, affects multiple Expat packages, including expat, expat-devel, and expat-static, which are crucial for applications relying on XML parsing.

Vulnerability Detail

CVE-2026-77214 is a security vulnerability that arises from improper handling of XML data, which could allow an attacker to exploit the library and potentially execute arbitrary code or cause a denial of service. This vulnerability is particularly concerning as it can lead to significant security breaches in applications that utilize the Expat library for XML parsing. The CVSS score for this vulnerability is 8.2, indicating a high level of severity that requires immediate attention.

How To Fix

Minimum fixed version

0:2.8.5-1.2.hum1

This is the first release that contains the fix.

sudo dnf update expat

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Workaround

If immediate updating is not feasible, consider implementing input validation and sanitization in your application to mitigate the risk of exploitation. Additionally, avoid processing untrusted XML data until the packages are updated.

Conclusion

The vulnerability CVE-2026-77214 poses a significant risk to applications using the Expat XML parser library. It is crucial to update the affected packages to the latest patched versions to ensure the security of your applications. Regular monitoring for vulnerabilities using tools like Vulert can help maintain the integrity of your software.

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