CVE-2026-28953 Overview
CVE-2026-28953 is a memory handling vulnerability affecting Apple's web content processing across multiple operating systems and Safari. Processing maliciously crafted web content may lead to an unexpected process crash. Apple addressed the issue with improved memory handling in Safari 26.5, iOS 18.7.9 and iPadOS 18.7.9, iOS 26.5 and iPadOS 26.5, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, and watchOS 26.5. The vulnerability falls under [CWE-119], improper restriction of operations within the bounds of a memory buffer. An attacker can trigger the flaw remotely without authentication by serving a crafted web page.
Critical Impact
A remote attacker can crash the affected process by delivering malicious web content, disrupting availability across Apple's consumer and enterprise device ecosystem.
Affected Products
- Apple iOS and iPadOS (versions prior to 18.7.9 and 26.5)
- Apple macOS Tahoe (versions prior to 26.5), tvOS, visionOS, and watchOS (versions prior to 26.5)
- Apple Safari (versions prior to 26.5)
Discovery Timeline
- 2026-05-11 - CVE-2026-28953 published to NVD
- 2026-05-13 - Last updated in NVD database
Technical Details for CVE-2026-28953
Vulnerability Analysis
The vulnerability resides in the web content processing component shared across Apple's operating systems and Safari. When the rendering engine parses maliciously crafted HTML, JavaScript, or related web resources, improper memory handling leads to an unexpected process crash. The flaw is classified under [CWE-119], indicating an operation accesses memory outside the intended buffer boundaries. The attack requires no privileges and no user interaction beyond loading the malicious content. Impact is limited to availability, meaning the process terminates but confidentiality and integrity are not directly compromised based on the advisory.
Root Cause
The root cause is improper memory handling during the processing of web content. Apple's advisories indicate the fix was implemented by improving memory handling logic, suggesting a boundary or lifetime management defect in the parser or renderer. Such defects typically arise from missing bounds checks, incorrect size calculations, or unsafe pointer arithmetic when processing untrusted input structures.
Attack Vector
The attack vector is network-based. An attacker hosts a crafted web page or injects malicious content into an existing site. When a user visits the page with a vulnerable Safari or WebKit-based application, the rendering engine processes the content and crashes. The vulnerability can also be triggered through embedded web views in third-party iOS, iPadOS, macOS, tvOS, visionOS, or watchOS applications that rely on the system WebKit framework.
No public proof-of-concept exploit is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. See the Apple Security Advisory 127110 for vendor technical details.
Detection Methods for CVE-2026-28953
Indicators of Compromise
- Unexpected and repeated crashes of Safari or com.apple.WebKit.WebContent processes following navigation to specific URLs.
- Crash reports in ~/Library/Logs/DiagnosticReports/ referencing WebKit or WebContent processes with memory access faults.
- Browser telemetry showing tab or renderer crashes correlated with specific domains or ad networks.
Detection Strategies
- Monitor endpoint telemetry for abnormal termination of WebKit-based processes on macOS, iOS, and iPadOS devices.
- Correlate web proxy or DNS logs with crash events to identify malicious content delivery sources.
- Inventory Apple devices against fixed versions to identify exposure across the fleet.
Monitoring Recommendations
- Centralize diagnostic and crash report collection from managed Apple endpoints into a SIEM for analysis.
- Alert on clusters of WebKit process crashes across multiple devices, which may indicate active exploitation attempts.
- Track outbound traffic to newly registered or low-reputation domains accessed shortly before crash events.
How to Mitigate CVE-2026-28953
Immediate Actions Required
- Update affected devices to Safari 26.5, iOS 18.7.9 or 26.5, iPadOS 18.7.9 or 26.5, macOS Tahoe 26.5, tvOS 26.5, visionOS 26.5, and watchOS 26.5.
- Prioritize patching of devices used for browsing untrusted web content or shared workstations.
- Validate patch deployment through mobile device management (MDM) compliance reporting.
Patch Information
Apple released patches across its product line. Refer to the official advisories: Apple Security Advisory 127110, Apple Security Advisory 127111, Apple Security Advisory 127115, Apple Security Advisory 127118, Apple Security Advisory 127119, Apple Security Advisory 127120, and Apple Security Advisory 127121.
Workarounds
- Restrict browsing to trusted sites via web content filtering or proxy policy until patches are deployed.
- Disable JavaScript in Safari for high-risk users where business workflows allow.
- Enforce MDM policies that require minimum OS versions for corporate network access.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
