What is the CVSS score of CVE-2025-43539?

CVE-2025-43539 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of iOS are affected by CVE-2025-43539?

CVE-2025-43539 is a high-severity memory corruption vulnerability affecting Apple's macOS, iOS, iPadOS, tvOS, visionOS, and watchOS that enables remote code execution through malicious file…

How to fix or mitigate CVE-2025-43539?

Within 24 hours: inventory all Apple devices across macOS (14.x, 15.x, 26.x), iOS/iPadOS (18.x, 26.x), tvOS, visionOS, and watchOS 26.x to identify scope of exposure; communicate advisory to users emphasizing caution with unexpected file attachments and downloads. Within 7 days: deploy email gateway rules to block potentially malicious file types associated with this vector; implement endpoint monitoring to detect unusual file processing behavior; consider restricting file opening capabilities in untrusted contexts where operationally feasible. Within 30 days: monitor Apple security advisories daily for patch availability and stage deployment workflow; review and test incident response procedures for potential endpoint compromise via file-based attack.

iOS CVE-2025-43539

HIGH

Out-of-bounds Write (CWE-787)

2025-12-12 product-security@apple.com

Apple iOS macOS Memory Corruption

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Apr 02, 2026 - 19:37 vuln.today

CVE Published

Dec 12, 2025 - 21:15 nvd

HIGH 8.8

DescriptionCVE.org

The issue was addressed with improved bounds checks. This issue is fixed in iOS 18.7.3 and iPadOS 18.7.3, iOS 26.2 and iPadOS 26.2, macOS Sequoia 15.7.3, macOS Sonoma 14.8.3, macOS Tahoe 26.2, tvOS 26.2, visionOS 26.2, watchOS 26.2. Processing a file may lead to memory corruption.

AnalysisAI

Memory corruption via out-of-bounds write in Apple operating systems allows remote attackers to execute arbitrary code when victims process a malicious file. The vulnerability affects macOS (Sonoma 14.x, Sequoia 15.x, Tahoe 26.x), iOS/iPadOS (18.x, 26.x), tvOS, visionOS, and watchOS 26.x. Despite a high CVSS score of 8.8, EPSS data indicates only 0.05% exploitation probability (15th percentile), and no public exploit code or active exploitation is confirmed. The flaw stems from inadequate bounds checking (CWE-787) in file processing routines, requiring user interaction but no authentication, making it a realistic phishing or malicious download target.

Technical ContextAI

This vulnerability represents a classic out-of-bounds write condition (CWE-787), also known as a buffer overflow, occurring in Apple's file processing subsystems. The flaw affects the core operating system layer across Apple's entire ecosystem, as indicated by CPE strings targeting macOS broadly without component-specific granularity. When the affected code processes specially crafted file formats, insufficient bounds validation allows data to be written beyond allocated memory boundaries. This class of vulnerability can corrupt adjacent memory structures, function pointers, or critical data, providing attackers control over program execution flow. The cross-platform nature-spanning mobile (iOS/iPadOS), desktop (macOS), embedded (watchOS), mixed reality (visionOS), and media devices (tvOS)-suggests the vulnerable code exists in a shared framework or library used across Apple's unified development environment, potentially CoreFoundation, ImageIO, or similar system-level components responsible for file format parsing.

RemediationAI

Immediately update all affected Apple devices to vendor-released patched versions that incorporate improved bounds checking mechanisms. For macOS Sonoma users, upgrade to version 14.8.3 or later; macOS Sequoia users should install version 15.7.3 or later; macOS Tahoe users require version 26.2 or later. iOS and iPadOS devices must be updated to either 18.7.3 or 26.2 depending on device compatibility. Similarly, tvOS, visionOS, and watchOS users should install version 26.2 or later. Organizations can deploy these updates through Mobile Device Management (MDM) systems for centralized patch management. Apple's security updates are available through System Settings > General > Software Update on macOS, and Settings > General > Software Update on iOS/iPadOS devices. Detailed security content documentation and direct download links are provided in Apple's security advisories at https://support.apple.com/en-us/125887 and https://support.apple.com/en-us/125888. No workarounds are published; patching remains the sole effective mitigation. Until patches are deployed, implement defense-in-depth controls including restricting users from opening untrusted files, disabling automatic file preview features, and enforcing strict email attachment policies.