A logic issue was addressed with improved state management. This issue is fixed in Safari 26.4, iOS 18.7.7 and iPadOS 18.7.7, iOS 26.4 and iPadOS 26.4, macOS Tahoe 26.4, visionOS 26.4. A malicious website may be able to access script message handlers intended for other origins.
26.4Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:LI:NA:N4.3/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N