Security Update 2019-005 (High Sierra and Sierra)

To keep older versions of macOS protected from the latest exploit, Apple has released Security Update 2019-005 for macOS 10.13 High Sierra and 10.12 Sierra. Just as with macOS Mojave 10.14.6 Supplemental Update 2, the updates address an out-of-bounds read with improved input validation to prevent a remote attacker from causing unexpected application termination or arbitrary code execution. The security updates are available from Software Update or Apple’s Support Downloads site. (Free. For 10.13.6 High Sierra, 1.9 GB; for 10.12.6 Sierra, 938.1 MB; release notes)