Thunderbird updates
From Updates, in the HARD wiki · Updated
This article is about security updates for Thunderbird. For every product, see Updates.
The latest version of Thunderbird is 159, which Mozilla released on 27 Oct 2026. It fixes 173 security flaws.[1] It fixes 173 security flaws, and attackers study each release to work out what it fixed.
Since June 2026, Mozilla has put out 10 Thunderbird security releases.
Should you update your Thunderbird?
Yes, this week. Thunderbird 159 came out on 27 Oct 2026. None of its 173 fixes is known to be used in attacks yet. Its page lists what each fix covers.
How to update
- Open Thunderbird.On a Mac choose Thunderbird → About Thunderbird; on Windows open the ☰ menu → Help → About Thunderbird.
- Let it download the update.The About window checks for one by itself; when it says “Restart to update Thunderbird”, click it.
To see which version you have: The same About Thunderbird window shows the version under the name.
Every release
Every Thunderbird security release since June 2026, newest first.
| Release | Date | Fixes | Used in attacks |
|---|---|---|---|
| Thunderbird 159 | 173 | – | |
| Thunderbird 158.0.1 | 8 | – | |
| Thunderbird 158 | 80 | – | |
| Thunderbird 157 | 76 | – | |
| Thunderbird 156 | 75 | – | |
| Thunderbird 155 | 30 | – | |
| Thunderbird 154 | 56 | – | |
| Thunderbird 153 | 61 | – | |
| Thunderbird 152.0.1 | 2 | – | |
| Thunderbird 152 | 40 | – |
References
- ^ Mozilla. “Mozilla Foundation Security Advisories”, each release’s notes.