Download Mozilla Thunderbird 78.4.2

Version 78.4.2 of Thunderbird has been released. Thunderbird is an open source client for e-mail and newsgroups, with features such as support for various mail and news accounts, a spam filter, spell checker, and a customizable appearance. In version 78 we find, among other things, a dark mode and other parts of the interface, such as the icons and the screen for composing an email, have also been overhauled. Furthermore, the Lightning calendar add-on is now a standard part of the program, there is a new wizard for the first use and only MailExtensions add-ons are supported. Version 78.4.2 was released to address a security issue.

CVE-2020-26950: Write side effects in MCallGetProperty opcode not accounted for
Impact: critical

Description

In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition.

References

• Bug 1675905