9.8 Critical

CVE-2026-84539 An out-of-bounds write issue was addressed with improved bounds checking

Description

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Golden Gate 27, macOS Tahoe 26.7.2. An app may be able to cause unexpected system termination.

CVSS 3.1 detail

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector: Network
Attack complexity: Low
Privileges required: None
Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Affected products and versions

Product	Affected versions	Fixed in
macOS 27	earliest → < 27	27
macOS 26.7	earliest → < 26.7.2	26.7.2

References

support.apple.com support.apple.com
support.apple.com support.apple.com

Timeline

Published October 26, 2026
Last modified November 4, 2026

The 3813 CVEs of macOS →

CVE-2026-86925 An authorization issue was addressed with improved state management 5.5 Medium CVE-2026-84627 A buffer overflow was addressed with improved bounds checking 7.8 High CVE-2026-113945 An out-of-bounds read was addressed with improved bounds checking 5.5 Medium CVE-2026-65327 A logic issue was addressed with improved checks 8.4 High

Track this CVE