Apple OS Kernel Memcorrupt (iOS18.7.2, watchOS26.1, macOS15.7.2) fixed 26.1
CVE-2025-43520 Published on December 12, 2025
A memory corruption issue was addressed with improved memory handling. This issue is fixed in watchOS 26.1, iOS 18.7.2 and iPadOS 18.7.2, macOS Tahoe 26.1, visionOS 26.1, tvOS 26.1, macOS Sonoma 14.8.2, macOS Sequoia 15.7.2, iOS 26.1 and iPadOS 26.1. A malicious application may be able to cause unexpected system termination or write kernel memory.
Known Exploited Vulnerability
This Apple Multiple Products Classic Buffer Overflow Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Apple watchOS, iOS, iPadOS, macOS, visionOS, tvOS, and iPadOS contain a classic buffer overflow vulnerability which could allow a malicious application to cause unexpected system termination or write kernel memory.
The following remediation steps are recommended / required by April 3, 2026: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vulnerability Analysis
CVE-2025-43520 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Classic Buffer Overflow Vulnerability?
The program copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. A buffer overflow condition exists when a program attempts to put more data in a buffer than it can hold, or when a program attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the "classic" case in which the program copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.
CVE-2025-43520 has been classified to as a Classic Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2025-43520
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Affected Versions
Apple macOS:- Version unspecified and below 14.8 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 15.7 is affected.
- Version unspecified and below 26.1 is affected.
- Version unspecified and below 18.7 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.