CVE-2018-4124: Apple iPhone OS

Critical severity, CVSS 9.8. EPSS: 5.9% chance of exploitation in the next 30 days.

An issue was discovered in certain Apple products. iOS before 11.2.6 is affected. macOS before 10.13.3 Supplemental Update is affected. tvOS before 11.2.6 is affected. watchOS before 4.2.3 is affected. The issue involves the "CoreText" component. It allows remote attackers to cause a denial of service (memory corruption and system crash) or possibly have unspecified other impact via a crafted string containing a certain Telugu character.

Affected products

• Apple iPhone OS: before 11.2.6 (fixed in 11.2.6)
• Apple Mac OS X: before 10.13.3 (fixed in 10.13.3)
• Apple tvOS: before 11.2.6 (fixed in 11.2.6)
• Apple watchOS: before 4.2.3 (fixed in 4.2.3)

Published 2018-04-03. Last modified 2026-06-17.