CVE-2025-43535 Overview
CVE-2025-43535 is a memory handling vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can trigger an unexpected process crash on affected devices. Apple addressed the flaw with improved memory handling in Safari 26.2, iOS 18.7.3, iPadOS 18.7.3, iOS 26.2, iPadOS 26.2, macOS Tahoe 26.2, and visionOS 26.2. The vulnerability requires user interaction, typically visiting an attacker-controlled webpage, to trigger the condition. The impact is limited to availability, resulting in denial of service through browser or renderer process termination.
Critical Impact
Attackers hosting malicious web content can crash browser or system processes on unpatched Apple devices, disrupting user sessions and potentially affecting system stability.
Affected Products
- Apple Safari (before 26.2)
- Apple iOS and iPadOS (before 18.7.3 and 26.2)
- Apple macOS Tahoe (before 26.2) and Apple visionOS (before 26.2)
Discovery Timeline
- 2025-12-17 - CVE-2025-43535 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-43535
Vulnerability Analysis
The vulnerability resides in the memory handling logic used to process web content across Apple's WebKit-based rendering pipeline. When the browser parses specially crafted HTML, CSS, or JavaScript payloads, memory is handled in a way that produces an inconsistent state. This inconsistency causes the affected process to terminate unexpectedly. The flaw affects Safari and every Apple operating system that ships the shared WebKit component, giving it broad platform reach. NVD categorizes the weakness as NVD-CWE-noinfo, indicating Apple did not publish detailed root cause information. The issue impacts availability only, with no confirmed path to code execution, information disclosure, or integrity compromise.
Root Cause
Apple's advisories describe the fix as "improved memory handling," which typically indicates a bounds, lifetime, or state tracking error inside WebKit. See the Apple Security Advisory #125884 for the vendor's official description. The absence of a specific CWE mapping suggests the underlying condition may involve a corner case in object lifecycle management rather than a classic buffer overflow.
Attack Vector
An attacker must lure a target to visit a malicious webpage or load hostile web content inside an application that embeds WebKit. Because the flaw is reachable over the network and requires only standard user interaction such as clicking a link, drive-by exploitation via phishing, malvertising, or compromised sites is realistic. Successful exploitation crashes the rendering process, producing a denial of service against the browser tab or embedding application.
No verified exploit code or public proof-of-concept is available. See the Apple Security Advisory #125885 for additional platform-specific notes.
Detection Methods for CVE-2025-43535
Indicators of Compromise
- Repeated Safari or WebKit-based application crashes correlating with visits to untrusted URLs.
- Crash reports in ~/Library/Logs/DiagnosticReports/ referencing WebKit, com.apple.WebKit.WebContent, or Safari on macOS.
- iOS and iPadOS crash logs from Settings > Privacy & Security > Analytics & Improvements referencing WebKit processes.
Detection Strategies
- Monitor endpoint telemetry for abnormal crash frequency in Safari, embedded WebViews, and other WebKit consumers.
- Correlate crash events with recent browsing history or inbound URLs from email and messaging clients.
- Flag hosts running Safari versions below 26.2 or Apple OS builds preceding the fixed releases.
Monitoring Recommendations
- Ingest macOS unified logs and iOS device analytics into a centralized logging platform for triage.
- Track outbound requests to newly observed domains that precede WebKit process terminations.
- Alert on user reports of unexpected browser tab or app crashes tied to specific web content.
How to Mitigate CVE-2025-43535
Immediate Actions Required
- Update Safari to version 26.2 on all supported macOS releases.
- Upgrade iOS and iPadOS devices to 18.7.3 or 26.2, depending on the supported track.
- Update macOS Tahoe systems to 26.2 and visionOS devices to 26.2.
- Inventory third-party applications that embed WebKit and confirm they receive OS updates.
Patch Information
Apple released fixes across the affected platforms in December 2025. Refer to the official advisories: Apple Security Advisory #125884, Apple Security Advisory #125885, Apple Security Advisory #125886, Apple Security Advisory #125891, and Apple Security Advisory #125892. Apply the patch matching each device's OS train.
Workarounds
- Restrict browsing to trusted sites and disable JavaScript on untrusted origins until patches are deployed.
- Use enterprise mobile device management (MDM) policies to enforce minimum OS versions on managed Apple fleets.
- Deploy web filtering to block known malicious domains that could deliver crafted web content.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
