Firefox ESR end of life: end of support by version
Mozilla · Browsers & Clients
For Firefox ESR by Mozilla, patchletter knows 4 support cycles. One of them has already ended and receives no more security updates. The next support window closes on 13/10/2026, that is in 37 days. The current version of Firefox ESR is 140.15.0esr. The cycles come from the open endoflife.date project, last reconciled on 04/09/2026.
When does support end for which Firefox ESR version?
A cycle is a maintained version line. Where a date is given, support ends on that day — after it the vendor ships no more security updates for that line.
| Cycle | Latest version | End of support | Status |
|---|---|---|---|
| 153 (aktueller ESR)LTS | 153.2.0 | no date on record | supported |
| 140LTS | 140.15.0 | 37 days left | EOL in 37 days |
| 128LTS | – | 355 days ago | End of Life |
| 115 (nur Windows 7/8/8.1 und macOS 10.12-10.14)LTS | 115.40.0 | no date on record | supported |
Which Firefox ESR versions no longer receive security updates?
1 of 4 cycles have ended. If you run one of those lines, the vendor ships you no more patches — not even for critical flaws.
- Firefox ESR 128
Where does the EOL data for Firefox ESR come from?
From the open endoflife.date project, which collects vendors' official support commitments. patchletter reconciles the cycles daily; the Firefox ESR data is as of 04/09/2026. In case of doubt the vendor's own lifecycle page applies — patchletter deliberately stores no vendor full texts.
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