Historical catalog analysis: CISA added this entry on December 15, 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-2025-43529 is a use-after-free vulnerability (CWE-416) located within the WebKit engine. The flaw occurs during the processing of maliciously crafted web content, which can result in memory corruption. Because WebKit serves as the underlying HTML processing engine for various Apple platforms and some non-Apple products, the vulnerability affects how these systems handle specific web data.
Exposure and applicability
This vulnerability applies to a broad range of assets utilizing WebKit for HTML parsing. Primary affected systems include:
* Apple Ecosystems: iOS, iPadOS, and macOS.
* Applications: Apple Safari and other integrated browsers or applications that rely on the WebKit framework.
* Third-Party Software: Any non-Apple products that utilize WebKit for web content rendering.
Exposure occurs when a user or system processes specially crafted web content via an affected browser or application. The inclusion of this CVE in the CISA Known Exploited Vulnerabilities (KEV) catalog as of December 15, 2025, indicates that the vulnerability is subject to active exploitation risks.
Remediation priorities
Our analysis suggests prioritizing remediation based on the asset’s exposure to untrusted web content. The following actions are recommended:
- Immediate Patch Deployment: Prioritize updates for user-facing devices (iOS, iPadOS, macOS) that frequently access external websites via Safari or WebKit-based apps.
- Vendor Guidance Review: Consult official Apple support documentation to identify the specific software versions that resolve CVE-2025-43529 across different hardware generations.
- Asset Inventory Audit: Identify non-Apple products in the environment that may rely on WebKit for HTML processing to determine if they require separate vendor updates.
- Service Decommissioning: If a legacy system is affected and no vendor mitigation is available, consider discontinuing use of the product to eliminate the exposure path.
How to validate remediation
Verification must go beyond simple version checks to ensure that the vulnerability has been addressed in the active runtime environment. Defenders should:
* Cross-Reference Patch Notes: Match installed build numbers against the specific security updates listed in vendor advisories for CVE-2025-43529.
* Configuration Audit: Verify that all WebKit-dependent applications on a single host have been updated, as updating the OS may not automatically update all third-party WebKit implementations.
Confirmation of a version update indicates the patch was applied; it does not independently prove that the memory corruption path is fully neutralized in every possible configuration.
Limits and open questions
While the vulnerability type (use-after-free) and the affected component (WebKit) are known, several factors remain uncertain. It is not explicitly stated whether this flaw can be triggered via passive browsing or if specific user interactions are required. Additionally, while CISA has flagged the vulnerability for federal agencies with a deadline of January 5, 2026, the specific exploit chain used in the wild remains undisclosed. Residual risk persists for devices that cannot be updated due to hardware age or those running third-party WebKit implementations where vendor patches are delayed.
Source and editorial note
CVE-2025-43529: Apple Multiple Products Use-After-Free WebKit Vulnerability · Source date: December 15, 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: December 18, 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: September 26, 2026 at 00:27 UTC.
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