CVE-2018-4256: Apple Mac OS X

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

In macOS High Sierra before 10.13.5, an out-of-bounds read was addressed with improved input validation.

Affected products

• Apple Mac OS X: before 10.13.5 (fixed in 10.13.5)

Published 2019-01-11. Last modified 2026-06-17.