Firefox updates
From Updates, in the HARD wiki · Updated
This article is about security updates for Firefox. For every product, see Updates.
The latest version of Firefox is 159.0.1, which Mozilla released on 3 Nov 2026. It fixes 1 security flaw.[1] None of its fixes is known to be used in attacks yet. Automatic updates will install it for you.
Since June 2026, Mozilla has put out 14 Firefox security releases.
Should you update your browser?
Yes, soon. Firefox 159.0.1 came out on 3 Nov 2026. None of its 1 fixes is known to be used in attacks yet. Its page lists what each fix covers.
How to update
- Open Firefox’s About window.Open the ☰ menu → Help → About Firefox. Firefox checks for the update and downloads it.
- Click Restart to update Firefox.Firefox reopens your windows and tabs. Until it restarts, the old, unfixed version keeps running.
- Leave automatic updates on.In Settings → General → Firefox Updates, keep “Automatically install updates” selected.
To see which version you have: The ☰ menu → Help → About Firefox shows the version.
Every release
Every Firefox security release since June 2026, newest first.
| Release | Date | Fixes | Used in attacks |
|---|---|---|---|
| Firefox 159.0.1 | 1 | – | |
| Firefox 159 | 167 | – | |
| Firefox 158.0.1 | 4 | – | |
| Firefox 158 | 77 | – | |
| Firefox 157.0.1 | 1 | – | |
| Firefox 157 | 76 | – | |
| Firefox 156 | 73 | – | |
| Firefox 155 | 29 | – | |
| Firefox 154 | 58 | – | |
| Firefox 153 | 63 | – | |
| Firefox 152.0.6 | 2 | – | |
| Firefox 152.0.4 | 1 | – | |
| Firefox 152 | 40 | – | |
| Firefox 151.0.3 | 2 | – |
References
- ^ Mozilla. “Mozilla Foundation Security Advisories”, each release’s notes.