Safari 12.1.2
Apple has released Safari 12.1.2 for macOS 10.13.6 High Sierra and 10.12.6 Sierra, fixing some unspecified bugs and patching security vulnerabilities that were also dealt with by the version included in 10.14.6 Mojave (see “Apple Releases macOS 10.14.6, iOS 12.4, watchOS 5.3, tvOS 12.4, and More,” 22 July 2019). In addition to fixing an inconsistent user interface issue that could lead to address bar spoofing, the update addresses over 20 WebKit-related issues, including memory corruption, handling of synchronous page loads, and universal cross-site scripting caused by processing maliciously crafted Web content. Safari 12.1.2 is available only via Software Update. (Free, 10.13.6 and 10.12.6)
Safari 12.1.2 wouldn’t install on my High Sierra iMac. I tried to install it from the App Store, but the install process reported an an odd error
Might be able to offer assistance if you tell us (or show us with a screenshot) what the “odd” error is.
The Safari 12.1.2 update for Sierra seems to have been pulled from the App Store.
I was able to download and install it on a MacBook Pro on September 12, but it couldn’t be found on an iMac on September 12 nor a Mac Pro on September 23.
Or is there a hardware compatibility issue with the two other (older) machines?