CVE-2026-28946 Overview
CVE-2026-28946 is a use-after-free vulnerability [CWE-416] in Apple Safari and macOS Tahoe. Processing maliciously crafted web content can trigger an unexpected Safari crash. Apple addressed the issue with improved memory management in Safari 26.5 and macOS Tahoe 26.5.
The flaw resides in Safari's web content processing path. An attacker hosting malicious web content can cause a denial-of-service condition when a user visits the page. The vulnerability requires user interaction but no authentication or elevated privileges.
Critical Impact
Remote attackers can crash Safari by serving malicious web content, causing availability loss on affected macOS systems.
Affected Products
- Apple Safari versions prior to 26.5
- Apple macOS Tahoe versions prior to 26.5
Discovery Timeline
- 2026-05-11 - CVE-2026-28946 published to NVD
- 2026-05-13 - Last updated in NVD database
Technical Details for CVE-2026-28946
Vulnerability Analysis
The vulnerability is a use-after-free condition in Safari's web content rendering pipeline. A use-after-free occurs when a program continues to reference memory after it has been freed. Attackers can leverage this state to cause crashes or, in some scenarios, influence memory contents.
In this case, Apple's advisory confirms the practical impact is an unexpected Safari crash when processing maliciously crafted web content. The vector is network-based and exploitation requires the victim to load attacker-controlled content. Apple resolved the issue with improved memory management in Safari 26.5 and macOS Tahoe 26.5.
Root Cause
The root cause is improper lifetime management of an object accessed during web content processing. A pointer remained reachable after the underlying memory was released, allowing subsequent operations to dereference a freed object. Apple's fix introduces stricter memory management to prevent the dangling reference.
Attack Vector
Exploitation requires a user to visit a malicious or compromised web page in a vulnerable Safari build. No credentials are required, and no prior access to the target system is needed. The advisory describes the outcome as an unexpected Safari crash, indicating an availability impact rather than confirmed code execution. See the Apple Support Document 127115 and Apple Support Document 127121 for vendor details.
No public proof-of-concept code has been published for CVE-2026-28946 at this time.
Detection Methods for CVE-2026-28946
Indicators of Compromise
- Repeated Safari crash reports referencing WebKit or web content processes on macOS endpoints.
- Outbound connections from Safari to newly registered or low-reputation domains immediately before crash events.
- Crash logs under ~/Library/Logs/DiagnosticReports/ naming com.apple.WebKit.WebContent near the time of user browsing activity.
Detection Strategies
- Inventory macOS endpoints and identify hosts running Safari or macOS builds older than 26.5.
- Correlate browser crash telemetry with URL access logs to identify potential exploitation attempts.
- Apply web filtering and threat intelligence feeds to block known malicious domains delivering exploit content.
Monitoring Recommendations
- Monitor macOS crash diagnostic reports for recurring com.apple.WebKit.WebContent terminations.
- Track Safari version compliance through endpoint management tooling and flag deviations from 26.5 or later.
- Alert on anomalous spikes in Safari renderer crashes across the fleet, which can indicate exploitation attempts.
How to Mitigate CVE-2026-28946
Immediate Actions Required
- Update Safari to version 26.5 and macOS to Tahoe 26.5 or later on all affected systems.
- Prioritize patching for users handling sensitive data or operating in high-risk roles.
- Communicate the issue to end users and advise caution when browsing untrusted sites until patches are applied.
Patch Information
Apple released fixes in Safari 26.5 and macOS Tahoe 26.5. Refer to the Apple Support Document 127115 and Apple Support Document 127121 for full release notes and download instructions.
Workarounds
- Use an alternative, fully patched browser on macOS systems where the Safari update cannot be applied immediately.
- Enforce DNS or proxy-based blocking of known malicious domains to reduce exposure to crafted web content.
- Restrict Safari usage on critical systems until macOS Tahoe 26.5 is deployed through your patch management process.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
