Firefox ESR 140
Firefox ESR 140 is supported. Mozilla provides security updates until October 13, 2026. Mozilla released it on June 24, 2025.
- Status
- Supported
- Released
- June 24, 2025
- Security updates until
- October 13, 2026
- Long-term support release
- Yes
- Official lifecycle page
- whattrainisitnow.com
- Checked on
The last ESR 140 release is 140.17, from September 29, 2026. Installations move to ESR 153 on October 13, 2026.
- Product
- Firefox ESR
- Version
- 140
- Sources
Page URL Mozilla release calendar https://whattrainisitnow.com/release/?version=esr