Macos High Sierra 10.13.1 May 2026

External USB 3.0 drives would sometimes unmount improperly after the Mac went into deep sleep. This persisted from 10.13.0 and was only partially mitigated in 10.13.1. Users were advised to disable "Put hard disks to sleep when possible" in Energy Saver preferences.

The headline security fix in macOS High Sierra 10.13.1 was the patch for KRACK (Key Reinstallation Attack). This WPA2 protocol vulnerability allowed attackers within range to decrypt network traffic, potentially stealing sensitive information. Apple backported the fix from beta versions of iOS and watchOS, making 10.13.1 a mandatory update for any Mac using public or corporate Wi-Fi.

No operating system update is without friction. Users updating to macOS High Sierra 10.13.1 reported several recurring issues, some of which were never fully resolved in this specific build.

If you are looking for the "headline feature" of High Sierra in general, that would be APFS (Apple File System) and HEVC Video Support, but those were introduced in the base 10.13.0 release. 10.13.1 is best characterized as the "Security and Emoji Update."

macOS High Sierra 10.13.1: A Deep Dive into Apple's Latest Operating System macos high sierra 10.13.1

On October 31, 2017, Apple released macOS High Sierra 10.13.1, a significant update to its desktop operating system. This incremental update built upon the foundation laid by macOS High Sierra 10.13, which was initially released on September 25, 2017. In this article, we'll take a closer look at the features, improvements, and changes introduced in macOS High Sierra 10.13.1.

Overview of macOS High Sierra

Before diving into the specifics of 10.13.1, let's briefly recap the key features and improvements introduced in macOS High Sierra 10.13:

What's New in macOS High Sierra 10.13.1

Now, let's explore the changes and improvements introduced in macOS High Sierra 10.13.1:

Under the Hood Changes

In addition to the user-facing changes, macOS High Sierra 10.13.1 includes several under-the-hood changes and improvements:

Installation and Upgrade

If you're running macOS High Sierra 10.13, you can easily upgrade to 10.13.1 through the Mac App Store. Simply follow these steps:

Conclusion

macOS High Sierra 10.13.1 is a solid incremental update that builds upon the foundation laid by its predecessor. While it may not introduce revolutionary new features, it provides important security patches, compatibility improvements, and under-the-hood changes that enhance the overall user experience. If you're running macOS High Sierra 10.13, it's recommended that you upgrade to 10.13.1 to ensure you have the latest security patches and improvements.

In the original 10.13 release, converting a Fusion Drive (a hybrid SSD+HDD setup) to APFS could result in data loss or an unbootable system. 10.13.1 explicitly disabled automatic APFS conversion for Fusion Drives and older rotational hard drives. Instead, the installer would leave those drives as HFS+ (Mac OS Extended) unless manually converted via Disk Utility after a full backup. External USB 3