CVE-2018-4257: Apple Mac OS X

Critical severity, CVSS 9.8. EPSS: 1.3% chance of exploitation in the next 30 days.

In macOS High Sierra before 10.13.5, a buffer overflow was addressed with improved size 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.