Browser maker Mozilla is urging users to update their Firefox instances to the latest version to avoid facing issues with using add-ons due to the impending expiration of a root certificate.
“On March 14, 2025, a root certificate used to verify signed content and add-ons for various Mozilla projects, including Firefox, will expire,” Mozilla said.
“Without updating to Firefox version 128 or higher (or ESR 115.13+ for ESR users, including Windows 7/8/8.1 and macOS 10.12-10.14 users), this expiration may cause significant issues with add-ons, content signing and DRM-protected media playback.”
Mozilla said the latest version of Firefox includes a new root certificate that will prevent this from happening. The update is crucial for all users of Firefox running a version prior to 128, or Extended Support Release (ESR) versions before 115.13, both of which were released on July 9, 2024. This includes all versions of Firefox for Windows, macOS, Linux, and Android.
Root certificates are designed to identify a root certificate authority (CA), a trusted entity that ensures the authenticity of websites, add-ons and software updates. In this case, the certificate is used to verify that a browser add-on was approved by Mozilla.
Should the digital certificate expire, systems that rely on the certificate can no longer meet authenticity and integrity guarantees, causing certain features like add-ons, alerts about breached passwords, or secure media playback to stop working.
In the event the update is not applied before the deadline, it also risks causing the blocklists used for flagging harmful add-ons and revocation lists for recognizing untrusted SSL certificates and preloaded intermediate certificates to go out-of-date, putting users at risk of more threats.
“While it’s possible to use Firefox without updating, you may experience problems such as add-ons being disabled, DRM media difficulties and other interruptions,” it added. “Skipping the update also means missing important security fixes and performance improvements.”
Users are highly advised to check and confirm they’re running Firefox version 128 and later by navigating to Menu > Settings > About Firefox. It’s worth noting that iOS and iPad users are unaffected. Given that the Tor Browser is a modified version of Firefox ESR, it’s essential that users update their installations as well.
