Zen Browser 1.21.15b has been released, featuring an upgrade to the Firefox 154 engine, cross-platform backup support for macOS, enhanced cookie management, and automatic language detection for translations. The update includes over sixty security fixes addressing critical vulnerabilities, ensuring users are protected against significant threats. Zen Browser has gained popularity with features that appeal to power users, and it maintains a consistent release schedule, distinguishing it from other Firefox forks. Users should be aware that there are some reported issues with password storage performance following the update, so caution is advised when updating
Zen Browser 1.21.15b Shipped: Firefox 154 Engine, macOS Backups, and 60+ Security Fixes
Zen Browser 1.21.15b shipped today on the stable channel, upgrading its engine from Firefox 153.0.4 to 154.0. The update brings cross-platform profile backup support for macOS, granular cookie exemption controls, and automatic language detection for full-page translations. Mozilla's MFSA2026-74 advisory landed alongside the release, patching over sixty CVEs including critical sandbox escapes and privilege escalation flaws in the Remote Settings and DOM networking stacks. Roughly every four-day release cadence in the 1.21 series signals serious momentum, though users should know that faster password storage performance is currently taking a hit following a recent architectural rewrite.
