CVE-2025-43457 Overview
CVE-2025-43457 is a use-after-free memory corruption vulnerability [CWE-416] affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can lead to an unexpected Safari crash. Apple addressed the issue with improved memory management across its browser and OS releases.
The vulnerability affects Safari on macOS and the WebKit-based browsing components shipped with iOS, iPadOS, visionOS, and watchOS. Exploitation requires a user to visit or interact with attacker-controlled web content, making drive-by web attacks the primary delivery vector.
Critical Impact
Attackers hosting malicious web content can trigger a use-after-free condition in Safari, causing browser crashes and potentially enabling further memory corruption on affected Apple devices.
Affected Products
- Apple Safari (versions prior to 26.1)
- Apple iOS and iPadOS (versions prior to 26.1)
- Apple macOS Tahoe (versions prior to 26.1), visionOS 26.1, and watchOS 26.1
Discovery Timeline
- 2025-11-04 - CVE-2025-43457 published to the National Vulnerability Database (NVD)
- 2026-07-15 - Last updated in NVD database
Technical Details for CVE-2025-43457
Vulnerability Analysis
CVE-2025-43457 is a use-after-free flaw in Safari's web content processing. A use-after-free vulnerability occurs when a program continues to reference memory after it has been freed, allowing an attacker to influence the contents of that memory region and alter program behavior.
According to Apple's advisories, processing maliciously crafted web content triggers the condition, resulting in an unexpected Safari crash. The user interaction requirement is satisfied by loading a webpage or rendering embedded content within Safari or a WebKit-backed view on iOS, iPadOS, visionOS, or watchOS.
Apple resolved the issue with improved memory management in Safari 26.1 and the corresponding OS releases. Consult the Apple Security Advisory 125632 and related advisories for release-specific details.
Root Cause
The root cause is improper lifetime management of a heap-allocated object within Safari's web content rendering pipeline. Code paths retain and dereference a pointer to memory that has already been released, producing undefined behavior when the freed allocation is reused.
Attack Vector
The attack vector is network-based and requires user interaction. An attacker hosts a webpage or delivers content that, when parsed by Safari, drives the vulnerable object through an allocation and release sequence that leaves a dangling reference. Subsequent access to the freed region crashes the browser and may be leveraged as a primitive in a larger exploit chain.
No public proof-of-concept, exploit code, or in-the-wild exploitation has been reported. The vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog.
Detection Methods for CVE-2025-43457
Indicators of Compromise
- Unexpected Safari or WebKit process crashes recorded in system diagnostic reports and CrashReporter logs on macOS, iOS, iPadOS, visionOS, and watchOS devices.
- Repeated user reports of Safari tab or app termination after visiting specific external URLs.
- Outbound connections from Safari to previously unseen or low-reputation domains preceding crash events.
Detection Strategies
- Monitor endpoint telemetry for abnormal termination of the Safari and com.apple.WebKit.WebContent processes.
- Correlate crash events with browser history and DNS resolutions to identify malicious content sources.
- Track deployment status of Safari 26.1 and OS 26.1 updates across the Apple device fleet to identify unpatched exposure.
Monitoring Recommendations
- Ingest macOS unified logs and iOS MDM crash telemetry into a central log platform for correlation.
- Alert on clusters of WebKit crashes originating from the same user, device group, or URL.
- Review web proxy logs for requests to domains associated with recent crash timestamps.
How to Mitigate CVE-2025-43457
Immediate Actions Required
- Update Safari to version 26.1 on macOS Tahoe and update iOS, iPadOS, visionOS, and watchOS devices to the 26.1 release train.
- Prioritize patching for users who routinely browse untrusted web content or handle sensitive data.
- Verify update installation across MDM-managed fleets and enforce compliance policies for out-of-date devices.
Patch Information
Apple has released fixes in Safari 26.1, iOS 26.1, iPadOS 26.1, macOS Tahoe 26.1, visionOS 26.1, and watchOS 26.1. Refer to Apple Security Advisory 125632, Advisory 125638, Advisory 125639, and Advisory 125640 for platform-specific package versions and release notes. Red Hat has published corresponding errata for downstream WebKitGTK consumers, including RHSA-2026:9692 and RHSA-2026:10702.
Workarounds
- Restrict browsing on unpatched devices to trusted sites and block access to unknown domains at the network perimeter until updates are applied.
- Use enterprise content filtering and DNS security to reduce exposure to malicious web content while patches are staged.
- Advise users to avoid opening untrusted links in email, messaging apps, or documents on devices that have not yet received the 26.1 update.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
