Mattermost 11.9 End of Life

Support dates and upgrade guidance — rebuilt from live data.

Supported

Mattermost 11.9 is actively supported. It reaches end of life on 15 Oct 2026.

67 days of security support left

11.9.0 latest release

26% of this branch's supported lifetime has elapsed — 16 Jul 2026 → 15 Oct 2026.

Check your versionsudo -u mattermost /opt/mattermost/bin/mattermost version

Support timeline

Official dates from the Mattermost release process.

Mattermost 11.9 is the newest branch — this is the longest runway currently available.

Branch	End of life	Days left	vs 11.9
Mattermost 11.9	15 Oct 2026	67	this branch
Mattermost 11.8	15 Sept 2026	37	-30 days
Mattermost 11.7	15 May 2027	279	+212 days
Mattermost 10.11	15 Aug 2026	6	-61 days

When does Mattermost 11.9 reach end of life?

Mattermost 11.9 reaches end of life on 15 Oct 2026 — 67 days from now. After that date it receives no security fixes.

Is Mattermost 11.9 still supported?

Yes. Mattermost 11.9 is currently maintained. Latest release: 11.9.0, published 8 Jul 2026.

What happens when Mattermost 11.9 reaches end of life?

Security fixes stop. After 15 Oct 2026 this branch receives no further updates under standard support.

How long do I have to upgrade from Mattermost 11.9?

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