Zen Browser 1.23.4b has been released, featuring a critical security fix for the eMudhra certificate compromise, which is embedded directly into the browser to protect users offline and under restrictive network policies. This update also includes a new "Focus" mode for its per-site customization feature, a performance improvement for Windows users, and several smaller bug fixes. Built on Firefox 158.0.1, Zen Browser aims to create a calmer internet experience and has gained popularity as an alternative to other browsers. Users are encouraged to update to this release to ensure they are protected against the recent security vulnerabilities

Zen Browser 1.23.4b Ships With eMudhra Certificate Fix and Firefox 158.0.1

Zen Browser 1.23.4b as a security-critical stable release built on Firefox 158.0.1. Its most important move is baking Mozilla's OneCRL block directly into the browser, protecting users against the eMudhra certificate compromise even offline or under restrictive network policy. Alongside the security work, Zen adds a "Focus" mode to its per-site Boosts feature and a CSIR PGO performance bump for Windows users. It rounds out the update with a stack of smaller bug fixes and the full MFSA2026-111 advisory, which Mozilla rated high impact.

Zen Browser 1.23.4b Ships With eMudhra Certificate Fix and Firefox 158.0.1 @ Linux Compatible