Mattermost 10.11 reaches end of life on August 15, 2026. It is one of only two releases in 55 that got a twelve-month support window instead of the usual three — and the newest release, 11.9, expires in 62 days. The upgrade that buys you the most time is an older version. Every date, and why.
The three-month rule, and the two exceptions
| Support window | Releases | What it means |
|---|---|---|
| 3 months | 42 | The standard. Roughly one release of overlap. |
| 4 months | 4 | Minor schedule slippage. |
| 9–10 months | 7 | Older, longer-cadence releases. |
| 12 months | 2 | The only two releases ever given a full year — 10.11 and 11.7. |
What's covered
- What actually stops on August 15
- The three-month rule, and the two exceptions
- The LTS label points at the wrong versions
- Why "upgrade to the latest" costs you time
- What is still supported on August 16
- What to do
Full guide with every version, risk scores, and live updates: https://endoflife.ai/article-mattermost-eol
