Checkmk 2.3 End of Life: Passive Maintenance Ends October 29, 2026
Checkmk 2.3 reaches end of life on October 29, 2026, the day its passive maintenance ends. Its active maintenance already ended on November 6, 2025. Both dates are from the version table in the Checkmk user guide. The same table puts Checkmk 2.4 at the end of its own active maintenance one day earlier, on October 28, 2026, so the last week of October changes the status of two versions at once.
Checkmk versions and their dates
| Version | Released | End of active maintenance | End of passive maintenance (end of life) |
|---|---|---|---|
| Checkmk 2.5 | April 28, 2026 | Six months after 3.0 is released; no date set | April 28, 2028 |
| Checkmk 2.4 | May 6, 2025 | October 28, 2026 | November 6, 2027 |
| Checkmk 2.3 | April 29, 2024 | November 6, 2025 | October 29, 2026 |
| Checkmk 2.2 | May 23, 2023 | Ended | November 23, 2025 |
Checkmk's table no longer lists 2.2 and says only that for older versions it highly recommends updating.
What the two phases mean
- Active maintenance: the stable version gets regular patch releases. It runs until six months after the next version is released, so two versions are actively maintained side by side for a while.
- Passive maintenance: generally another year. Fixes are made mainly on request through support contracts, although Checkmk may release them to everyone.
- After passive maintenance: end of life. Checkmk's stated minimum is 24 months of error and security corrections per major version.
What to do
- On Checkmk 2.2 or older: already past end of life. Update now.
- On Checkmk 2.3: the last day is October 29, 2026. Checkmk publishes an update matrix in its user guide; check it before planning the path to a newer version.
- On Checkmk 2.4: regular patches stop on October 28, 2026, and fixes continue on request until November 6, 2027. If you want a version that is still actively patched after October, that is 2.5.
- Check what it runs on. The Linux distribution under the Checkmk server has its own end date; our EOL Checker answers that.
Frequently Asked Questions
When is Checkmk 2.3 end of life?
October 29, 2026, the end of passive maintenance in the Checkmk user guide's version table. Active maintenance for 2.3 ended on November 6, 2025.
Is Checkmk 2.4 still supported?
Yes. Checkmk 2.4 is in active maintenance until October 28, 2026 and then in passive maintenance until November 6, 2027.
What is the difference between active and passive maintenance in Checkmk?
In active maintenance a stable version receives regular patch releases; that lasts until six months after the next version is released. Passive maintenance generally lasts another year, and fixes are made mainly on request through support contracts, although they may be released to everyone.
Related
- Checkmk — every version, live status and EOL Risk Score
- The 2026 end-of-life calendar
- How we verify our dates