High severity · published May 11, 2026
CVE-2026-28991
An out-of-bounds read was addressed with improved bounds checking
7.5
CVSS
0.6%
EPSS
No
On KEV
Description
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. An app may be able to cause a denial-of-service.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
macOS · Apple
before 15.8.2; before 26.5 · source: vendor, NVD
IO
iOS · Apple
before 26.5 · source: NVD
IA
iOS and iPadOS · Apple
before 26.5 · source: vendor
TV
tvOS · Apple
before 26.5 · source: vendor, NVD
VI
visionOS · Apple
before 26.5 · source: vendor, NVD
WA
watchOS · Apple
before 26.5 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28991
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-28991
Release Notes
https://support.apple.com/en-us/127110
Release Notes
https://support.apple.com/en-us/127115
Release Notes
https://support.apple.com/en-us/127118
Release Notes
https://support.apple.com/en-us/127119
Release Notes
https://support.apple.com/en-us/127120
support.apple.com
https://support.apple.com/en-us/149523
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