Out-of-bounds write in macOS - CVE-2025-43400

Vulnerability identifier: #VU116173

CSH Severity: High

CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-43400

CWE-ID: CWE-787

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error within the FontParser component. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger an out-of-bounds write and execute arbitrary code on the target system.

macOS
tvOS
iPadOS
Apple iOS
visionOS
watchOS

Install updates from vendor's website.

macOS - addressed in versions 26.0.1 25A362, 14.8.1 23J30, 15.7.1 24G231
tvOS - update to 26.1 23J580
iPadOS - addressed in versions 18.7.1 22H31, 26.0.1 23A355
Apple iOS - addressed in versions 18.7.1 22H31, 26.0.1 23A355
visionOS - update to 26.0.1
watchOS - update to 26.1 23S37

• https://support.apple.com/en-us/125328

• Remote code execution in macOS Tahoe
• Remote code execution in macOS Sonoma
• Remote code execution in macOS Sequoia
• Remote code execution in Apple iOS 26 and iPadOS 26
• Remote code execution in Apple iOS 18 and iPadOS 18
• Remote code execution in Apple visionOS
• Multiple vulnerabilities in Apple tvOS
• Multiple vulnerabilities in Apple watchOS