CVE-2018-4251: Apple Mac OS X

Medium severity, CVSS 5.5. EPSS: 1.2% chance of exploitation in the next 30 days.

An issue was discovered in certain Apple products. macOS before 10.13.5 is affected. The issue involves the "Firmware" component. It allows attackers to modify the EFI flash-memory region that a crafted app that has root access.

Affected products

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

Published 2018-06-08. Last modified 2026-06-17.