CVE-2018-4111: Apple Mac OS X

Medium severity, CVSS 5.9. EPSS: 1.1% chance of exploitation in the next 30 days.

An issue was discovered in certain Apple products. macOS before 10.13.4 is affected. The issue involves the "Mail" component. It allows man-in-the-middle attackers to read S/MIME encrypted message content by sending HTML e-mail that references remote resources but lacks a valid S/MIME signature.

Affected products

• Apple Mac OS X: before 10.13.4 (fixed in 10.13.4)

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