CVE-2018-4111: An issue was discovered in certain Apple products.

Security readout for executives and security teams

This flaw weakens the confidentiality promised by S/MIME encrypted email in Apple Mail on macOS before 10.13.4. A network-positioned attacker could cause encrypted message content to be exposed through specially crafted HTML email referencing remote resources without a valid S/MIME signature. Exposure is most likely where Apple Mail on macOS versions before 10.13.4 processes S/MIME encrypted email, especially in environments that allow HTML email and remote resource loading. Treat this as a confidentiality risk for sensitive encrypted email, not a broad system takeover issue. Prioritize remediation for executives, legal, finance, and security teams using S/MIME in Apple Mail. Mitigation focus: Update affected macOS systems to 10.13.4 or later per Apple guidance.; Check Apple’s advisory for supported security update paths.; Restrict remote content loading in email clients where feasible..

Prepared

Jun 7, 2026, 14:03 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.