CVE-2025-43511: Apple iPadOS Use-After-Free Vulnerability

CVE-2025-43511 Overview

CVE-2025-43511 is a use-after-free vulnerability [CWE-416] affecting Apple's web content processing stack across multiple operating systems. Processing maliciously crafted web content can trigger an unexpected process crash. Apple addressed the flaw with improved memory management in Safari 26.2, iOS 18.7.2, iPadOS 18.7.2, iOS 26.2, iPadOS 26.2, macOS Tahoe 26.2, visionOS 26.2, and watchOS 26.2. The attack vector is network-based and requires user interaction, such as visiting an attacker-controlled webpage. No public exploit or in-the-wild exploitation has been reported.

Critical Impact
Remote attackers can crash the web content process by serving crafted web content to a vulnerable Apple device, resulting in denial of service against browser and WebKit-based applications.

Affected Products

Apple iOS prior to 18.7.2 and 26.2
Apple iPadOS prior to 18.7.2 and 26.2
Apple Safari, macOS Tahoe, visionOS, and watchOS prior to 26.2

Discovery Timeline

2025-12-12 - CVE-2025-43511 published to NVD
2026-06-30 - Last updated in NVD database

Technical Details for CVE-2025-43511

Vulnerability Analysis

The issue is a use-after-free condition in Apple's web content handling components, tracked under [CWE-416]. A use-after-free occurs when a program continues to use a pointer to memory after that memory has been freed, allowing the freed region to be reallocated and reinterpreted. In this case, processing maliciously crafted web content forces the renderer to reference a stale object, corrupting execution state and terminating the process.

Apple's advisories list the impact as an unexpected process crash rather than arbitrary code execution. However, use-after-free primitives in browser engines have historically served as building blocks for sandboxed code execution when combined with heap-shaping techniques. The confidentiality and integrity impacts are rated none, while availability is rated high because the affected renderer process fails.

Root Cause

Apple's advisory attributes the flaw to improper object lifetime tracking in the WebKit content handling path. An object referenced during page rendering is released while another code path retains a live pointer to it. Subsequent dereference of that pointer accesses reclaimed memory. The vendor fix was described as "improved memory management," which typically implies stronger reference counting or refactored ownership semantics around the affected object.

Attack Vector

Exploitation requires an attacker to deliver crafted HTML, JavaScript, or related web content to the victim. Delivery paths include direct navigation to a malicious site, embedded iframes on compromised sites, malvertising, or in-app WebViews that render remote content. User interaction is required, consistent with the UI:R element of the CVSS vector. Successful exploitation causes the web content process to terminate. See the Apple Support Document #125633 for vendor details.

Detection Methods for CVE-2025-43511

Indicators of Compromise

Repeated WebContent or Safari renderer crash reports on iOS, iPadOS, macOS, visionOS, or watchOS devices
Crash logs referencing WebKit frames with signals such as SIGSEGV or EXC_BAD_ACCESS during page rendering
Users reporting Safari tab reloads or in-app browser instability after visiting specific URLs

Detection Strategies

Ingest device crash telemetry and MDM diagnostics into a central SIEM to identify clusters of WebContent process failures
Correlate crash events with recently visited URLs and referrer data to identify suspicious domains
Monitor threat intelligence feeds for reports of WebKit exploitation campaigns targeting versions prior to iOS/iPadOS 26.2

Monitoring Recommendations

Track OS build versions across managed Apple devices to identify hosts still running vulnerable releases
Alert on newly registered domains serving heavy JavaScript or WebAssembly content accessed from corporate devices
Review MDM compliance reports weekly to confirm rollout of the fixed OS versions

How to Mitigate CVE-2025-43511

Immediate Actions Required

Update all Apple devices to Safari 26.2, iOS 18.7.2 or 26.2, iPadOS 18.7.2 or 26.2, macOS Tahoe 26.2, visionOS 26.2, or watchOS 26.2
Push the update through MDM policies to enforce compliance on managed fleets
Advise users to avoid untrusted links and to close browser tabs exhibiting repeated crashes

Patch Information

Apple released fixes across its product line in the December 2025 security updates. Refer to the vendor advisories: Apple Support Document #125884, Apple Support Document #125886, Apple Support Document #125890, Apple Support Document #125891, and Apple Support Document #125892. Red Hat also shipped rebuilds of the affected WebKitGTK components — see Red Hat CVE-2025-43511 for the full errata list.

Workarounds

Disable JavaScript in Safari for high-risk browsing sessions until patches are applied
Restrict in-app WebView usage to a controlled set of trusted domains via network filtering
Use enterprise browser policies to block newly registered or low-reputation domains

bash

# Verify iOS/iPadOS build version via MDM query or device Settings
# Settings > General > About > Software Version
# Target: 18.7.2, 26.2, or later