Apple has today released iOS 12.5.4 for older devices not compatible with iOS 14, bringing fixes for several security vulnerabilities that could lead to arbitrary code execution if exploited.
As this update appears to have been released to address a small number of specific issues, our expectation is that it does not contain any accessibility changes for blind and low vision users; however, if you notice any changes, improvements or regressions in your own use of this release, please post a comment with your findings.
The update is available for iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and iPod touch (6th generation).
Apple's release notes for iOS 12.5.4 simply state that the update, "Introduces important security updates and is recommended for all users."
How to update
iOS 12.5.4 is available via Over-the-Air Update (Settings > General > Software Update) via Finder on a Mac with macOS Catalina or later, or via iTunes on a PC or Mac with macOS Mojave or earlier.
Before updating, we strongly recommend making a full and complete backup of your device (either locally or in iCloud, depending on personal preference). This will ensure that, in the unlikely event that something goes wrong during the update process, you will have a current backup on hand in case a device restore becomes necessary. Also, if using OTA update, we recommend plugging your device into a power source for the duration of the download/installation process, so as to prevent the unlikely event of your battery going dead during the update.
More information on how to update the software on your device is available on this Apple Support page.