macOS Rapid Security Response (RSR) & Software Update Management

1. What is Rapid Security Response (RSR)?

Introduced in macOS 13 Ventura and refined in macOS Sequoia, Rapid Security Response (RSR) delivers critical security updates between major software releases—without requiring a full OS reboot or lengthy installation process.

RSR updates apply patches directly to Safari, the WebKit framework, and core system libraries using a cryptographic overlay volume mounted over the Signed System Volume (SSV).

2. RSR Version Supplemental Letters

RSR updates append supplemental letters in parentheses to the OS version string (e.g., macOS 14.5 (a), macOS 14.5 (b)).

3. Command Line Management of Software Updates

# Check for pending software updates and RSR patches
softwareupdate -l

# Download all available software updates in the background
softwareupdate -d -a

# Force download and installation of active updates
sudo softwareupdate -i -a --restart

4. Managing RSR Deferrals via MDM Profiles

Enterprise administrators can control RSR behavior using the com.apple.applicationaccess payload keys:

• allowRapidSecurityResponseInstallation: Controls user manual installation.
• allowRapidSecurityResponseRemoval: Controls user rollback capability.
• enforcedSoftwareUpdateDelay: Defers minor OS releases while allowing immediate RSR patches.

5. Frequently Asked Questions (FAQ)