# MA-1347.062025: MyCERT Advisory - Security Updates – Mozilla Thunderbird and Firefox

**Date:** 20 Jun 2025  
**Source:** https://www.mycert.org.my/portal/advisory?id=MA-1347.062025  
**Advisory ID:** MA-1347.062025

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**1.0 Introduction**
Recently, Mozilla has released security updates to address multiple high-severity vulnerabilities in its Thunderbird and Firefox.
**2.0 Impact**
These vulnerabilities could allow attackers to execute arbitrary code, crash applications, exhaust disk space, and leak sensitive credentials.
**3.0 Affected Products**
- Thunderbird versions prior to 139.0.2
- Thunderbird versions prior to 128.11.1
- Firefox versions prior to 139.0.4
**4.0 Recommendations**
CyberSecurity Malaysia encourages users and administrators to review the following [Mozilla security advisory](https://www.mozilla.org/en-US/security/advisories/) and apply the necessary updates:
Kindly refer to the following URLs for more information: 
- <https://www.mozilla.org/en-US/security/advisories/mfsa2025-50/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2025-49/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2025-47/>
Generally, we advise users of these devices to be updated with the latest security announcements by the vendor and follow best practice security policies to determine which updates should be applied.
For further enquiries, please contact Cyber999 Incident the Response Centre through the following channels:
E-mail: cyber999[at]cybersecurity.my 
Phone: 1-300-88-2999 (monitored during business hours) 
Mobile: +60 19 2665850 (24x7 call incident reporting) 
Business Hours: Mon - Fri 08:30 -17:30 MYT 
Web: <https://www.cybersecurity.my>
**5.0    References**
- <https://www.mozilla.org/en-US/security/advisories/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2025-50/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2025-49/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2025-47/>