Mozilla Firefox end of life: end of support by version
Mozilla · Browsers & Clients
For Mozilla Firefox by Mozilla, patchletter knows 4 support cycles. None of them has ended so far. The next support window closes on 15/09/2026, that is in 9 days. The current version of Mozilla Firefox is 155.0.1. The cycles come from the open endoflife.date project, last reconciled on 04/09/2026.
When does support end for which Mozilla Firefox 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 |
|---|---|---|---|
| 155 (Rapid Release) | 155.0 | 9 days left | EOL in 9 days |
| 153 ESRLTS | 153.2.0 | no date on record | supported |
| 140 ESRLTS | 140.15.0 | 37 days left | EOL in 37 days |
| 115 ESR (nur Altsysteme)LTS | 115.40.0 | no date on record | supported |
Which Mozilla Firefox versions no longer receive security updates?
No Mozilla Firefox cycle has ended according to the data on record. That covers only the lines listed here — older cycles that endoflife.date no longer carries are not included.
Where does the EOL data for Mozilla Firefox come from?
From the open endoflife.date project, which collects vendors' official support commitments. patchletter reconciles the cycles daily; the Mozilla Firefox 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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