Mozilla Releases Firefox 158 With JPEG XL Support and 77 Security Fixes
Firefox 158.0 arrives on the desktop release channel with official JPEG XL support and fixes for 77 CVEs, while Firefox ESR branches receive fixes the same day.
Mozilla released Firefox 158.0 on the desktop release channel on October 13, 2026 (US time), bringing official support for the JPEG XL image format and a batch of security fixes. The release was reported by forest.watch.impress.co.jp.
JPEG XL support is now official in Firefox 158 after being tested in Firefox Labs since Firefox 152. The format has also drawn recent attention as Rust-based JPEG XL decoders were added to Microsoft Edge and Google Chrome.
Firefox 158 also changes how scroll positions are handled: they are no longer rounded to screen pixels, which Mozilla says makes scrolling smoother and more accurate, particularly on high-resolution displays or when the page is zoomed in.
The release fixes 77 vulnerabilities by CVE count: 30 rated High, 33 Moderate and 14 Low severity. No Critical severity vulnerability fixes are included in Firefox 158. On the same day, the Firefox ESR 153.5 and 115.43 branches also received security fixes.
Quick answers
When was Firefox 158 released?
Firefox 158.0 was released on the desktop release channel on October 13, 2026 (US time).
Does Firefox 158 support JPEG XL?
Yes. Firefox 158 adds official support for the JPEG XL image format, which had been tested in Firefox Labs since Firefox 152.
How many vulnerabilities does Firefox 158 fix?
Firefox 158 fixes 77 vulnerabilities by CVE count: 30 High, 33 Moderate and 14 Low severity. No Critical severity fixes are included.