Critical Security Update for Mozilla Firefox: Addressing Multiple Vulnerabilities
Summary
ALSA-2026:47105: Important: firefox security update. Affects firefox versions < 140.13.0-1.el8_10.alma.1. Fixed in 140.13.0-1.el8_10.alma.1. How to fix ↓
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Background
Mozilla Firefox is a widely-used open-source web browser known for its commitment to standards compliance, performance, and user privacy. It supports various web technologies and is designed to provide a secure browsing experience. However, recent vulnerabilities have been identified that could compromise its security, affecting both Firefox and Thunderbird users.
Vulnerability Detail
This vulnerability stems from multiple security flaws within Mozilla Firefox, including heap buffer overflows, use-after-free errors, and privilege escalation issues. These vulnerabilities can lead to serious consequences such as unauthorized access, data leakage, and potential system compromise. The vulnerabilities are associated with various components, including the JavaScript engine, networking, and audio/video processing, making them critical to address promptly.
How To Fix
Minimum fixed version
140.13.0-1.el8_10.alma.1
This is the first release that contains the fix.
sudo dnf update firefoxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, users can disable certain features that may be exploited until the update is applied. For example, disabling JavaScript can mitigate some risks, but this may affect the functionality of many websites. To disable JavaScript in Firefox, go to 'about:config' in the address bar, search for 'javascript.enabled', and toggle it to 'false'.
Conclusion
In summary, Mozilla Firefox has released a critical security update to address multiple vulnerabilities that could compromise user security. It is essential for users to update their browsers to the latest version to mitigate these risks. Additionally, temporary workarounds can be employed until the update is applied.
See every vulnerability recorded for firefox →
FAQ
The update addresses multiple vulnerabilities, including heap buffer overflows, use-after-free errors, and privilege escalation issues across various components.
You can check your Firefox version by going to 'Help' > 'About Firefox'. Compare it with the patched version 140.13.0-1.el8_10.alma.1.
If you cannot update immediately, consider disabling JavaScript or other features that may be vulnerable until you can apply the update.
More details can be found on the CVE pages associated with the vulnerabilities, such as CVE-2026-15718 and CVE-2026-16390.
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