CVE-2025-43501 Overview
CVE-2025-43501 is a buffer overflow vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can trigger an unexpected process crash. Apple addressed the issue with improved memory handling across 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 flaw is categorized under [CWE-787] (Out-of-Bounds Write) and [CWE-120] (Classic Buffer Overflow). Exploitation requires user interaction, such as visiting a malicious webpage. The current impact is limited to availability, resulting in denial of service through process termination rather than code execution or data exposure.
Critical Impact
A remote attacker can crash Safari or WebKit-based processes by luring a user to visit crafted web content, disrupting browsing sessions across iOS, iPadOS, macOS, and visionOS devices.
Affected Products
- Apple Safari (prior to 26.2)
- Apple iOS and iPadOS (prior to 18.7.3 and 26.2)
- Apple macOS Tahoe (prior to 26.2) and Apple visionOS (prior to 26.2)
Discovery Timeline
- 2025-12-17 - CVE-2025-43501 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-43501
Vulnerability Analysis
The vulnerability is a buffer overflow condition triggered when Apple's web rendering stack processes maliciously crafted web content. When the affected code paths handle attacker-controlled inputs, memory writes exceed the intended buffer boundary. This out-of-bounds write corrupts adjacent memory, causing the rendering process to terminate unexpectedly.
Apple has not published exploitation details, and the advisories describe the outcome as an unexpected process crash. The vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog, and no public proof-of-concept is available.
Root Cause
The root cause is improper memory handling in a WebKit-related component shared across Safari, iOS, iPadOS, macOS Tahoe, and visionOS. Missing or insufficient bounds checking allows write operations to extend beyond allocated buffer regions. Apple's patch introduces improved memory handling to enforce correct boundary checks.
Attack Vector
The attack vector is network-based and requires user interaction. A victim must load attacker-controlled web content, such as a malicious page or an embedded frame, in Safari or another WebKit-consuming application. Successful triggering of the flaw crashes the browser or rendering process. Confidentiality and integrity are unaffected based on the published CVSS metrics.
The vulnerability manifests during web content parsing within the affected memory routine. See the Apple security advisories linked below for vendor-specific technical context.
Detection Methods for CVE-2025-43501
Indicators of Compromise
- Repeated unexpected crashes of Safari or WebKit-based processes shortly after visiting external URLs.
- Crash reports referencing memory corruption or out-of-bounds write in WebKit rendering components.
- Web sessions terminating consistently on specific attacker-hosted domains.
Detection Strategies
- Monitor endpoint crash telemetry for Safari, WebContent, and related WebKit helper processes.
- Correlate browser crashes with recent network access to newly observed or low-reputation domains.
- Review MDM and EDR inventory data to identify devices running Safari or OS builds older than the fixed versions.
Monitoring Recommendations
- Ingest macOS and iOS crash logs into centralized logging for review by incident response teams.
- Track outbound HTTP/HTTPS destinations from vulnerable endpoints and flag anomalies preceding crash events.
- Alert on repeated ReportCrash or com.apple.WebKit.WebContent termination events across a fleet.
How to Mitigate CVE-2025-43501
Immediate Actions Required
- Update Safari to version 26.2 on supported macOS systems.
- Update iPhone and iPad devices to iOS 18.7.3, iPadOS 18.7.3, iOS 26.2, or iPadOS 26.2 as applicable.
- Update Apple Vision Pro to visionOS 26.2 and Mac systems to macOS Tahoe 26.2.
- Enforce patch deployment through MDM policies and verify compliance across managed devices.
Patch Information
Apple released fixes in Safari 26.2, iOS 18.7.3 and iPadOS 18.7.3, iOS 26.2 and iPadOS 26.2, macOS Tahoe 26.2, and visionOS 26.2. Refer to the vendor advisories: Apple Security Advisory #125884, Apple Security Advisory #125885, Apple Security Advisory #125886, Apple Security Advisory #125891, and Apple Security Advisory #125892.
Workarounds
- Restrict browsing to trusted sites until patches are applied on all affected devices.
- Deploy DNS or web-proxy filtering to block access to low-reputation and newly registered domains.
- Use MDM configuration profiles to disable JavaScript in Safari for high-risk user groups where operationally feasible.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
