Zen Browser 1.21.9b has been released, built on Firefox 153.0, and includes features such as HDR video playback for Windows, native multi-PDF merging, and compliance with EU QWAC/eIDAS for enterprise authentication. This version also addresses a significant security patch, inheriting Mozilla's MFSA2026-68 advisory that fixes 44 CVEs, including critical vulnerabilities. Users can expect improvements in container management, Globe-F keyboard support on macOS, and various bug fixes that enhance overall functionality. The release, while labeled stable, carries a beta tag, and the upgrade is recommended for those seeking enhanced productivity and security in their browsing experience

Zen Browser 1.21.9b Ships With Firefox 153.0 and a 44-CVE Security Patch

Zen Browser 1.21.9b has shipped, built on Firefox 153.0 and featuring HDR video playback for Windows, native multi-PDF merging, and EU QWAC/eIDAS compliance for enterprise authentication. The release inherits Mozilla’s massive MFSA2026-68 security advisory, patching 44 CVEs including critical sandbox escapes and use-after-free vulnerabilities. Beyond the underlying security sweep, users will also notice refined container management, Globe-F keyboard support on macOS, and fixes for Space Routing and essential menu friction. The build is available now across Windows, macOS, and Linux, offering a low-friction upgrade for those relying on the productivity-focused Firefox fork.

Zen Browser 1.21.9b Ships With Firefox 153.0 and a 44-CVE Security Patch @ Linux Compatible