Apple released this week’s 26.2 developer betas, and the first public betas followed soon after. Alongside those, Apple pushed Release Candidate 1 builds for two maintained macOS lines: Sequoia 15.7.3 with build 24G407, and Sonoma 14.8.3 with build 23J208.
These RCs arrive as routine maintenance updates for Macs that remain on macOS 15 or macOS 14. Apple classifies them as security-focused releases. Expect fixes that improve stability and protect older systems that have not moved to macOS 26 yet.
Apple also plans to ship Safari 26.2 as a separate browser update for macOS 15 and macOS 14, independent of these RCs. That keeps WebKit protections current across supported branches.
What’s new
macOS Sequoia 15.7.3 RC 1 (24G407). This build targets security corrections and reliability improvements for Macs staying on macOS 15. Apple continues to provide security updates for Sequoia through 2027, and this RC follows that track.
macOS Sonoma 14.8.3 RC 1 (23J208). Sonoma also receives a security-focused RC to keep devices on macOS 14 protected. Apple lists macOS 14 as supported for security updates through 2026, and 14.8.3 fits into that maintenance window.
Availability. The RC 1 builds are live for registered developers, and they typically appear for public beta testers shortly after. Build identifiers confirm delivery: 24G407 for 15.7.3 and 23J208 for 14.8.3.
How to update
- On your Mac, open System Settings.
- Select General, then Software Update.
- If you are on the developer or public beta channel, install macOS 15.7.3 RC 1 or macOS 14.8.3 RC 1 when it appears.
- Restart to finish.
If you spotted changes beyond security fixes in these RCs, tell us what you found in the comments.
