Apple Image I/O Out-of-Bounds Write (CVE-2025-43300)

Historical catalog analysis: CISA added this entry on August 21, 2025. 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-2025-43300 is an out-of-bounds write vulnerability (CWE-787) located within the Image I/O framework. This framework is used by Apple operating systems to handle image data. The flaw was added to CISA’s Known Exploited Vulnerabilities catalog on August 21, 2025.

Exposure and applicability

This vulnerability affects assets running the following Apple operating systems:
* iOS
* iPadOS
* macOS

Exposure exists where these systems utilize the Image I/O framework to process image files. Because this is a core system component, any application or system process that parses images via this framework may be an entry point.

Remediation priorities

Our analysis suggests prioritizing remediation based on the asset’s exposure to untrusted external data (e.g., user-facing devices and internet-connected workstations).

1. Apply Vendor Updates: The primary corrective action is the application of mitigations provided by Apple. Organizations should prioritize updates for devices that frequently process third-party image files.
2. Cloud Service Review: For organizations utilizing cloud services, we recommend reviewing configurations in alignment with BOD 22-01 guidance to ensure managed instances are updated.
3. Asset Decommissioning: In scenarios where a device cannot be patched and the risk is deemed unacceptable, the source suggests discontinuing use of the product.

How to validate remediation

To verify that exposure has been reduced, defenders should move beyond simple version checks. We recommend the following validation steps:
* Patch Confirmation: Verify through system management tools that the specific vendor-supplied security update addressing CVE-2025-43300 has been successfully installed and initialized.
* Configuration Audit: Ensure that automated update mechanisms are active and that no legacy versions of the Image I/O framework remain active on the system.

It is important to note that a version number alone does not prove the vulnerability is mitigated; confirmation must be tied to the successful application of the specific fix.

Limits and open questions

There are several unknowns regarding this vulnerability. The source does not specify if it is being used by ransomware campaigns, listing this status as “Unknown.” Additionally, while CISA has set a remediation deadline of September 11, 2025, for federal agencies, this date is a regulatory requirement for those entities and not a technical expiration of the vulnerability.

Residual risk remains if users are unable to update due to hardware limitations or if third-party applications bypass standard framework protections. The effectiveness of any mitigation depends on the complete application of vendor instructions across all affected device types.

Source and editorial note

CVE-2025-43300: Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability · Source date: August 21, 2025 · 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: August 24, 2025. 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: October 05, 2026 at 00:09 UTC.

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