CVE-2026-65331: Apple Safari DOS Vulnerability

CVE-2026-65331 Overview

CVE-2026-65331 is a denial-of-service vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can trigger an unexpected Safari crash. The root cause is an improper state management issue [CWE-703] within the browser's web content handling logic. Apple addressed the flaw through improved state management in Safari 26.6.1, iOS 18.7.10 and iPadOS 18.7.10, iOS 26.6.1 and iPadOS 26.6.1, and macOS Tahoe 26.6.2. Exploitation requires a user to visit or load attacker-controlled web content, giving the attack a network vector with user interaction.

Critical Impact
Successful exploitation crashes Safari, disrupting user browsing sessions and potentially causing loss of unsaved work across Apple desktop and mobile platforms.

Affected Products

Apple Safari (versions prior to 26.6.1)
Apple iOS and iPadOS (versions prior to 18.7.10 and 26.6.1)
Apple macOS Tahoe (versions prior to 26.6.2)

Discovery Timeline

2026-08-17 - CVE-2026-65331 published to NVD
2026-08-18 - Last updated in NVD database

Technical Details for CVE-2026-65331

Vulnerability Analysis

The vulnerability resides in Safari's handling of specific web content states. When the browser processes maliciously crafted HTML, JavaScript, or related web resources, the underlying WebKit rendering engine reaches an unexpected internal state. This condition results in an unhandled fault and abrupt process termination. The issue falls under [CWE-703], which covers improper check or handling of exceptional conditions. Only availability is affected. Confidentiality and integrity remain intact based on the CVSS vector published by Apple.

Root Cause

Apple's advisory attributes the flaw to improper state management inside Safari's web content processing pipeline. The affected code paths failed to validate or transition state correctly when handling adversarially structured input. Apple's fix introduces improved state management to reject or safely handle the malformed conditions that previously triggered the crash.

Attack Vector

An attacker hosts or injects malicious web content on a page a target visits. Loading the page in an unpatched Safari build forces the crash. Delivery methods include phishing links, malicious advertisements, compromised sites, or web content embedded through iframes. The vulnerability does not require authentication and does not yield code execution or data disclosure. No public proof-of-concept exploit is available at this time, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

No verified exploit code is available. See the Apple Support Document 148281 and related advisories for vendor technical details.

Detection Methods for CVE-2026-65331

Indicators of Compromise

Repeated unexpected Safari process terminations correlated with specific web page loads.
Crash reports referencing WebKit state transitions in ~/Library/Logs/DiagnosticReports/ on macOS.
User reports of Safari crashes after navigating to unfamiliar external links or advertisements.

Detection Strategies

Monitor endpoint telemetry for abnormal com.apple.Safari or com.apple.WebKit.WebContent process exits.
Correlate browser crash events with recent URL navigation history to isolate malicious content sources.
Ingest macOS unified logs and iOS crash analytics into a centralized data lake for cross-device pattern analysis.

Monitoring Recommendations

Track Safari and WebKit version strings across managed fleets to flag hosts running vulnerable builds.
Alert on clusters of Safari crashes affecting multiple users referencing the same domain or URL pattern.
Review MDM compliance dashboards for iOS, iPadOS, and macOS devices lagging on the required update baseline.

How to Mitigate CVE-2026-65331

Immediate Actions Required

Update Safari to version 26.6.1 on macOS endpoints.
Update iPhones and iPads to iOS 18.7.10, iPadOS 18.7.10, iOS 26.6.1, or iPadOS 26.6.1 as applicable.
Update macOS systems to macOS Tahoe 26.6.2.
Deploy updates through MDM to enforce compliance across managed Apple devices.

Patch Information

Apple released patches through the advisories linked below. Administrators should validate versions after deployment.

Workarounds

Restrict browsing to trusted sites until patches are applied across the fleet.
Use enterprise web filtering to block newly registered or low-reputation domains that may host malicious content.
Advise users to avoid clicking unsolicited links delivered via email, messaging, or advertisements.

bash

# Verify Safari version on macOS
mdls -name kMDItemVersion /Applications/Safari.app

# Verify macOS build version
sw_vers