Apple has released a Supplemental Update for macOS 10.14.5 targeting the MacBook Pro 15-inch model. According to the release notes for the update, this Supplemental Update addresses a firmware issue affecting 15-inch MacBook Pro computers that come with the T2 Security chip. Apple recommends this update for all T2 chip equipped MacBook Pro users.
This MacBook Pro Supplemental Update comes a week after Apple has released macOS 10.14.5. Apple has not specified the exact issue that has been fixed in this release, only mentioning that the issue being fixed is a firmware issue.
Here’s the text from the release note:
The MacBook Pro Supplemental Update addresses a firmware issue affecting 15-inch MacBook Pro computers with T2 Security Chip, and is recommended for all users.
The T2 Security chip is found in MacBook Pro models released in 2018 or later along with other models of Macs.
If you own a 15-inch MacBook Pro with T2 Security chip, then head over to System Preferences’s Software Update section in order to download the Supplemental Update on your computer. The update has a download size of 1.27GB. You can also download the update directly from Apple’s website here.