Firefox 158 End of Life

Support dates and upgrade guidance — rebuilt from live data.

Supported

Firefox 158 is actively supported. It reaches end of life on 27 Oct 2026.

7 days of security support left

158.0 latest release

50% of this branch's supported lifetime has elapsed — 13 Oct 2026 → 27 Oct 2026.

Check your versionfirefox --version

Support timeline

Official dates from the Firefox release process.

Firefox 158 is the newest branch — this is the longest runway currently available.

Branch	End of life	Days left	vs 158
Firefox 158	27 Oct 2026	7	this branch
Firefox 115	31 Mar 2027	162	+155 days

When does Firefox 158 reach end of life?

Firefox 158 reaches end of life on 27 Oct 2026 — 7 days from now. After that date it receives no security fixes.

Is Firefox 158 still supported?

Yes. Firefox 158 is currently maintained. Latest release: 158.0, published 13 Oct 2026.

What happens when Firefox 158 reaches end of life?

Security fixes stop. After 27 Oct 2026 this branch receives no further updates under standard support.

How long do I have to upgrade from Firefox 158?

7 days. This is already the newest branch, so this is the longest runway currently available.