Apple Multiple Products Classic Buffer Overflow Vulnerability (CVE-2025-43520)

Apple watchOS, iOS, iPadOS, macOS, visionOS, and tvOS contain a classic buffer overflow vulnerability which could allow a malicious application to cause unexpected system termination or write kernel memory.

Published Dec 12, 2025 · Updated May 29, 2026

X LinkedIn

Why patchRisk explained in plain English

Worst-case scenarioIf unpatched

A local attacker, with a low-privilege account, can achieve partial data exposure, complete denial of service or system unavailability. Federal agencies are required to remediate by 2026-04-03 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Classic Buffer Overflow (CWE-120) vulnerability in Apple Multiple Products. A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 18.7.2 and iPadOS 18.7.2, iOS 26.1 and iPadOS 26.1, macOS Sequoia 15.7.2, macOS Sonoma 14.8.2, macOS Tahoe 26.1, tvOS 26.1, visionOS 26.1, watchOS 26.1. A malicious application may be able to cause unexpected system termination or write kernel memory. Exploitation requires local access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●Apple Device Administrators

●Endpoint Security

●IT Security

●Running ipados: v < 18.7.2, 26.0; iphone os: v < 18.7.2, 26.0; macos: 14.0 ≤ v < 14.8.2, 15.0 ≤ v < 15.7.2, 26.0; tvos: v < 26.1; visionos: v < 26.1; watchos: v < 26.1

Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://cloud.google.com/blog/topics/threat-intelligence/darksword-ios-exploit-chain/

How to patch

Get the fix

Apply the fixed package from your vendor. The advisory lists affected versions and the exact fixed build.

↗ Vendor advisory

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.