# MA-1005.122023: MyCERT Advisory - Mozilla Releases Security Updates for Firefox and Thunderbird

**Date:** 22 Dec 2023  
**Source:** https://www.mycert.org.my/portal/advisory?id=MA-1005.122023  
**Advisory ID:** MA-1005.122023

---

**1.0 Introduction**
Recently, Mozilla has released security updates to address vulnerabilities in Firefox and Thunderbird.
**2.0 Impact**
A cyber threat actor could exploit some of these vulnerabilities to take control of an affected system.
**3.0 Affected Products**
Mozilla Firefox and Mozilla Thunderbird.
**4.0 Recommendations**
MyCERT encourages users and administrators to review the following advisories and apply the necessary updates:
- [Firefox 121](https://www.mozilla.org/en-US/security/advisories/mfsa2023-56/) : <https://www.mozilla.org/en-US/security/advisories/mfsa2023-56/>
- [Thunderbird 115.6](https://www.mozilla.org/en-US/security/advisories/mfsa2023-55/) : <https://www.mozilla.org/en-US/security/advisories/mfsa2023-55/>
- [Firefox ESR 115.6](https://www.mozilla.org/en-US/security/advisories/mfsa2023-54/) : <https://www.mozilla.org/en-US/security/advisories/mfsa2023-54/>
Generally, MyCERT advises the users of this 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 MyCERT 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 09:00 -18:00 MYT 
Web: <https://www.mycert.org.my> 
Twitter: <https://twitter.com/mycert> 
Facebook: <https://www.facebook.com/mycert.org.my>
**5.0    References**
- <https://www.cisa.gov/news-events/alerts/2023/12/20/mozilla-releases-security-updates-firefox-and-thunderbird>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2023-56/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2023-55/>
- <https://www.mozilla.org/en-US/security/advisories/mfsa2023-54/>