Historical catalog analysis: CISA added this entry on March 20, 2026. The entry reflects catalog information retrieved on August 31, 2026, not a snapshot archived on the inclusion date. Check current vendor guidance before acting.
What the vulnerability is
CVE-2025-43520 is a classic buffer overflow (CWE-120) identified across several Apple operating systems. The flaw allows a malicious application to trigger unexpected system termination or perform writes to kernel memory. This vulnerability was added to CISA’s Known Exploited Vulnerabilities catalog on March 20, 2026.
Exposure and applicability
The vulnerability affects a broad range of Apple hardware and software ecosystems, specifically:
* iOS and iPadOS
* macOS
* watchOS
* tvOS
* visionOS
Exposure is primarily tied to the execution of malicious applications on these platforms. Because this flaw impacts kernel memory, it represents a significant risk to system integrity across both mobile and desktop Apple environments.
Remediation priorities
Our analysis suggests prioritizing remediation based on the asset’s exposure to untrusted third-party applications and its role in handling sensitive data.
- Immediate Patching: Organizations should apply vendor-supplied updates for all affected operating systems according to Apple’s specific instructions for each product line.
- Federal Compliance: U.S. federal agencies are subject to a CISA-mandated remediation deadline of April 3, 2026.
- Cloud Service Review: For cloud-integrated services, defenders should align their response with BOD 22-01 guidance.
- Decommissioning: In scenarios where mitigations are unavailable for legacy hardware or software versions, the source recommends discontinuing use of the product.
How to validate remediation
Verification must move beyond simple version checks to ensure the vulnerability is actually mitigated. We recommend the following validation approach:
- Patch Confirmation: Verify that the installed OS build matches or exceeds the specific version identified by Apple as containing the fix for CVE-2025-43520.
- Configuration Audit: For managed fleets (via MDM), confirm that updates have been successfully pushed and applied across all device types, including wearables (watchOS) and peripherals (tvOS).
- Deployment Verification: Ensure that the update process completed without errors; a pending restart may leave the system exposed despite the patch being downloaded.
Limits and open questions
While vendor updates address the buffer overflow, residual risk remains if users continue to install applications from untrusted sources. It is currently unknown whether this vulnerability has been utilized in known ransomware campaigns. Furthermore, while patching reduces the likelihood of exploitation, it does not eliminate the inherent risk associated with kernel-level vulnerabilities if new bypasses are discovered.
Source and editorial note
CVE-2025-43520: Apple Multiple Products Classic Buffer Overflow Vulnerability · Source date: March 20, 2026 · Retrieved August 31, 2026.
Material facts are tied to the cited primary source. Recommendations are independent defensive analysis unless attributed to the source. Confirm consequential decisions against current authoritative guidance.
Archive date: March 23, 2026. The displayed post date is assigned three days after the source date to organize this retrospective archive; it does not mean this site published the analysis then. First published by this site: September 17, 2026 at 00:18 UTC.
Request a Vulnerability Assessment
Turn security intelligence into action.
Discuss your exposure, priorities, and the evidence needed to validate the outcome.
Request a security assessment ↗