Some 2015-era Macs running Sierra can be upgraded as far as macOS Monterey (12.0) .
: Addressed over 30 security vulnerabilities, including critical kernel fixes to prevent unauthorized code execution. Enterprise Fixes macossierra10126frenchiso
For the safest results, download the official installer from the Mac App Store and use a Terminal command (like hdiutil ) to convert the .dmg to a .iso yourself. Some 2015-era Macs running Sierra can be upgraded
If you are on a Mac and want to turn this ISO into a bootable USB drive to fix an older machine: Mount the ISO : Double-click the ISO file to open it. Find the App : Look for "Installer macOS Sierra" inside. Drag it to your Applications Use Terminal macossierra10126frenchiso