Another set of security vulnerabilities was recently addressed by Mozilla with the release of Thunderbird 60.5.1. All four security issues are rated as having High impact, and are likely to affect Thunderbird’s confidentiality (leak private data), integrity (cause crashes), and/or availability (prevent normal operation).
To update Thunderbird, click its hamburger menu icon at the top right, then select
About Thunderbird to show your installed version. If a newer version is available, you should see a button offering to install it.