Thunderbird 78.4.2 fixes a critical vulnerability

The team behind the Thunderbird email app has released version 78.4.2. This is a maintenance release that includes one important security fix for a recently discovered critical vulnerability.

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Thunderbird is my preferred email client of choice. I use this app on every PC and on every operating system I use. It is stable, contains all the features you need, supports add-ons and also comes with a useful RSS reader. I am using Thunderbird for many years and never felt the need to look for an alternative.

Thunderbird 78 doesn't support classic XUL add-ons any more, but includes some of their features natively. E.g. on Windows you can minimize the app to the system tray.

The following changes have been made in versions 78.4.2

What's in Thunderbird 78.4.2


This release fixes a flaw that was found at the Tianfu Cup Hackathon.

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

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

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The release notes are available here.


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