CVE-2026-64719: Apple Safari DOS Vulnerability

CVE-2026-64719 Overview

CVE-2026-64719 is an out-of-bounds access vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content may lead to an unexpected Safari crash. The flaw is categorized under [CWE-125] (Out-of-Bounds Read) and stems from insufficient bounds checking in the affected browser components. Apple addressed the issue through improved bounds checking across its product line. Remote attackers can trigger the condition over the network by luring a user to open specially crafted web content, making this a client-side attack requiring user interaction.

Critical Impact
Remote attackers can crash Safari and potentially disrupt the availability of Apple client devices through maliciously crafted web content delivered over the network.

Affected Products

Apple Safari (versions prior to 26.6)
Apple iOS and iPadOS (versions prior to 26.6)
Apple macOS Tahoe, tvOS, visionOS, and watchOS (versions prior to 26.6)

Discovery Timeline

2026-07-27 - CVE-2026-64719 published to the National Vulnerability Database
2026-07-28 - CVE-2026-64719 last modified in NVD

Technical Details for CVE-2026-64719

Vulnerability Analysis

The vulnerability resides in Safari's handling of web content, where an out-of-bounds access condition occurs during parsing or rendering. When Safari processes attacker-controlled content, memory access outside allocated buffer boundaries can trigger an unexpected termination of the browser process. This behavior aligns with [CWE-125] Out-of-Bounds Read weakness patterns. Apple's advisories confirm the fix was delivered by adding improved bounds checking to the affected code paths. The vector requires user interaction, typically visiting a malicious URL or opening a crafted web page. Confidentiality impact is high in the CVSS metric, indicating potential memory disclosure alongside the availability impact.

Root Cause

The root cause is missing or insufficient boundary validation when Safari accesses memory during web content processing. Apple's patch notes describe the remediation as "improved bounds checking," indicating the pre-patch code failed to validate index or length values against buffer bounds before dereferencing memory.

Attack Vector

Attackers deliver maliciously crafted web content to a target user through a controlled website, a compromised site, an advertising redirect, or an embedded frame. When Safari or an application using the WebKit rendering engine on affected Apple platforms parses the content, the out-of-bounds access triggers. The attack requires user interaction but no authentication, and it is executed remotely over the network.

No verified proof-of-concept code is publicly available for CVE-2026-64719. Refer to the Apple Security Updates portal for advisory details.

Detection Methods for CVE-2026-64719

Indicators of Compromise

Unexpected Safari or WebKit-based application crashes on macOS, iOS, iPadOS, tvOS, visionOS, or watchOS devices
Repeated com.apple.WebKit.WebContent process termination events in system logs following web browsing activity
Crash reports referencing out-of-bounds memory access in WebKit-related frames

Detection Strategies

Aggregate crash reports from Apple endpoints and correlate them with recently visited URLs to spot patterns of exploitation attempts
Monitor endpoint telemetry for anomalous browser process crashes coinciding with new domains or suspicious referrers
Inspect network proxy logs for connections to newly registered domains delivering scripted or media-heavy content immediately before Safari crashes

Monitoring Recommendations

Enable centralized collection of macOS and iOS diagnostic reports through mobile device management (MDM) solutions
Track Safari and OS version compliance across the fleet to identify devices still running versions prior to 26.6
Alert on repeated WebContent process terminations from the same user account within short time windows

How to Mitigate CVE-2026-64719

Immediate Actions Required

Update Safari to version 26.6 and upgrade affected Apple operating systems to their 26.6 releases (iOS, iPadOS, macOS Tahoe, tvOS, visionOS, watchOS)
Prioritize patching internet-facing user devices that browse untrusted web content
Advise users to avoid clicking on unsolicited links until updates are applied

Patch Information

Apple released fixes across its product line. See the vendor advisories for each platform: Apple Security Update 128066, 128067, 128068, 128069, 128070, and 128073. The fix applies improved bounds checking to the vulnerable code paths.

Workarounds

Restrict browsing to trusted sites through DNS filtering or secure web gateway policies until patches are deployed
Disable JavaScript for untrusted zones in Safari preferences where feasible
Enforce MDM policies that require Safari 26.6 or later before allowing corporate resource access

bash

# Verify Safari version on macOS
defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString

# Check macOS version
sw_vers -productVersion