CVE-2025-43368 Overview
CVE-2025-43368 is a use-after-free vulnerability [CWE-416] in Apple Safari and related operating system components. Processing maliciously crafted web content can trigger an unexpected Safari crash. Apple addressed the flaw through improved memory management in Safari 26, iOS 26, iPadOS 26, and macOS Tahoe 26.
The vulnerability requires user interaction, such as visiting an attacker-controlled webpage. The impact is limited to availability, resulting in a Safari process crash rather than code execution or data disclosure. Apple published the fix on September 15, 2025, and Siemens later referenced the issue in advisory SSA-032379 for downstream product exposure.
Critical Impact
Maliciously crafted web content can cause a Safari crash across iOS, iPadOS, macOS, and standalone Safari installations, creating denial-of-service conditions for browser users.
Affected Products
- Apple Safari (versions prior to Safari 26)
- Apple iOS and iPadOS (versions prior to iOS 26 / iPadOS 26)
- Apple macOS (versions prior to macOS Tahoe 26)
Discovery Timeline
- 2025-09-15 - CVE-2025-43368 published to NVD and patched in Safari 26, iOS 26, iPadOS 26, and macOS Tahoe 26
- 2025-09-22 - Issue referenced on the OSS-Security mailing list
- 2026-06-17 - Last updated in the NVD database
Technical Details for CVE-2025-43368
Vulnerability Analysis
The vulnerability is a use-after-free condition [CWE-416] in Safari's web content handling. A use-after-free occurs when a program continues to reference a memory region after it has been freed. When the freed memory is reallocated or contains attacker-controlled data, dereferencing the stale pointer leads to undefined behavior, most commonly a crash.
Apple's advisory characterizes the outcome as an unexpected Safari crash rather than arbitrary code execution. The confidentiality and integrity impact is rated none, while availability impact is low. The attack originates over the network and requires the user to load malicious web content.
The EPSS score for this CVE is 0.717%, placing it in the 49th percentile of exploit likelihood.
Root Cause
The root cause is improper lifetime management of an object within Safari's rendering or JavaScript engine components. A pointer to a heap object continued to be used after the underlying memory had been freed. Apple's remediation involves improved memory management, typically achieved by clearing dangling references, adopting smart pointer wrappers, or tightening object ownership rules.
Attack Vector
An attacker hosts or delivers crafted HTML, CSS, or JavaScript that triggers the vulnerable code path. When a user visits the page in an unpatched Safari version, Safari references freed memory and crashes. No authentication is required, but user interaction in the form of navigation to the malicious content is necessary.
No public proof-of-concept exploit is currently available, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog. Full details are documented in the Apple Support Advisory #125108 and Apple Support Advisory #125113.
Detection Methods for CVE-2025-43368
Indicators of Compromise
- Repeated unexplained Safari process terminations or WebContent process crashes on macOS, iOS, or iPadOS
- Crash reports referencing WebKit modules following visits to untrusted or newly encountered domains
- Endpoint logs showing Safari relaunches shortly after outbound requests to unknown web hosts
Detection Strategies
- Inventory endpoints and mobile devices to identify Safari, iOS, iPadOS, and macOS versions predating the Safari 26 / iOS 26 / iPadOS 26 / macOS Tahoe 26 release train
- Correlate browser crash telemetry with web proxy logs to identify pages that consistently trigger WebContent crashes
- Monitor for user-reported browser instability tied to specific URLs and preserve resulting crash dumps for triage
Monitoring Recommendations
- Ingest macOS unified logs and iOS crash reports into a centralized analytics platform to baseline browser stability
- Track outbound HTTP(S) traffic to newly registered or low-reputation domains that could host crash-triggering content
- Alert on abnormal frequency of Safari or WebKit crashes across managed fleets to surface targeted campaigns early
How to Mitigate CVE-2025-43368
Immediate Actions Required
- Upgrade to Safari 26, iOS 26, iPadOS 26, and macOS Tahoe 26 across all managed Apple endpoints
- Enforce update deployment through Mobile Device Management (MDM) policies for iOS, iPadOS, and macOS fleets
- Review Siemens Advisory SSA-032379 for any embedded WebKit exposure in industrial products
Patch Information
Apple released fixes on September 15, 2025. Refer to the vendor advisories for build numbers and download links: Apple Support Advisory #125108, Apple Support Advisory #125110, and Apple Support Advisory #125113. The patch replaces the vulnerable memory handling logic with improved lifetime management to eliminate the dangling pointer condition.
Workarounds
- Where patching is not immediately feasible, restrict Safari usage to trusted sites via web content filtering and secure web gateway policies
- Encourage users to avoid opening links from untrusted sources and to use alternative hardened browsers for high-risk browsing until patched
- Disable JavaScript for untrusted origins in Safari settings to reduce the attack surface for web-driven memory corruption
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
