Published May 11, 2026Sources checked Oct 26, 2026
7.5HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-28991 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.4%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-28991?
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 26.5 and iPadOS 26.5, macOS Sequoia 15.8.2, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, watchOS 26.5.