CVE-2026-20652: Apple Systems Denial of Service Vulnerability

CVE-2026-20652 Overview

CVE-2026-20652 is a memory handling vulnerability affecting multiple Apple products including macOS Tahoe, iOS, iPadOS, visionOS, and Safari. The vulnerability stems from improper memory handling (CWE-400: Uncontrolled Resource Consumption) that can be exploited by a remote attacker to cause a denial-of-service condition. Apple has addressed this issue with improved memory handling in the affected product updates.

Critical Impact

A remote attacker can exploit this vulnerability over the network without authentication to cause a denial-of-service, potentially disrupting availability of affected Apple devices and applications.

Affected Products

• macOS Tahoe versions prior to 26.3
• iOS 18.7.5 and iPadOS 18.7.5 (and earlier versions)
• iOS 26.3 and iPadOS 26.3 (versions prior to 26.3)
• visionOS versions prior to 26.3
• Safari versions prior to 26.3

Discovery Timeline

• 2026-02-11 - CVE-2026-20652 published to NVD
• 2026-02-12 - Last updated in NVD database

Technical Details for CVE-2026-20652

Vulnerability Analysis

This vulnerability is classified as CWE-400 (Uncontrolled Resource Consumption), indicating that the affected Apple software components fail to properly manage memory resources during certain operations. The flaw allows remote attackers to trigger excessive resource consumption, leading to a denial-of-service condition.

The vulnerability can be exploited over the network without requiring any privileges or user interaction, making it a significant concern for organizations using affected Apple products. The impact is limited to availability—no confidentiality or integrity compromise has been identified—but the ease of exploitation combined with the broad attack surface across multiple Apple platforms elevates the risk profile.

Root Cause

The root cause of CVE-2026-20652 lies in improper memory handling within the affected Apple software components. When processing certain malformed or specially crafted input, the software fails to adequately validate or constrain memory allocation and usage patterns. This can result in uncontrolled resource consumption that exhausts system memory or other resources, causing the application or system to become unresponsive.

Attack Vector

The attack vector for CVE-2026-20652 is network-based, allowing remote exploitation without authentication. An attacker can craft malicious network requests or content that triggers the vulnerable memory handling code path. Given that Safari is among the affected products, web-based attack scenarios are particularly relevant—visiting a malicious webpage or loading attacker-controlled content could trigger the vulnerability.

The exploitation requires no privileges and no user interaction, meaning the attack can be executed silently against vulnerable systems. The vulnerability affects the availability of the target system but does not enable data exfiltration or system compromise.

Detection Methods for CVE-2026-20652

Indicators of Compromise

• Unusual memory consumption patterns in Safari, WebKit processes, or system services on affected Apple devices
• Repeated application crashes or system hangs when processing web content or network data
• Abnormal network traffic patterns targeting Apple devices from untrusted sources
• System logs showing out-of-memory conditions or resource exhaustion events

Detection Strategies

• Monitor system resource utilization for anomalous memory consumption spikes on Apple endpoints
• Implement network intrusion detection rules to identify potentially malicious traffic targeting Safari or WebKit
• Deploy endpoint detection solutions capable of identifying denial-of-service attack patterns
• Review crash reports and system logs for patterns consistent with resource exhaustion attacks

Monitoring Recommendations

• Enable detailed logging on Apple devices to capture memory-related warnings and errors
• Implement alerting for sudden increases in memory utilization across managed Apple device fleets
• Monitor network perimeter for unusual traffic volumes targeting Apple device user agents
• Utilize SentinelOne's behavioral AI to detect anomalous process behavior indicative of DoS exploitation

How to Mitigate CVE-2026-20652

Immediate Actions Required

• Update all affected Apple devices to the latest patched versions immediately
• Prioritize updating Safari browsers across all managed macOS systems
• Review and restrict network access to untrusted content sources where feasible
• Enable automatic updates on Apple devices to ensure timely patch deployment

Patch Information

Apple has released security updates addressing CVE-2026-20652 across all affected platforms. The following versions contain the fix:

• macOS Tahoe 26.3 - See Apple Support Advisory #126346
• iOS 26.3 and iPadOS 26.3 - See Apple Support Advisory #126347
• iOS 18.7.5 and iPadOS 18.7.5 - See Apple Support Advisory #126348
• visionOS 26.3 - See Apple Support Advisory #126353
• Safari 26.3 - See Apple Support Advisory #126354

Organizations should verify patch deployment through mobile device management (MDM) solutions and software inventory tools.

Workarounds

• Limit Safari and web browsing to trusted sites until patches can be applied
• Consider using alternative browsers temporarily on macOS if Safari cannot be updated immediately
• Implement web content filtering to block potentially malicious content
• Enable network-level protections to filter suspicious traffic destined for Apple devices

# Verify macOS version to confirm patch status
sw_vers -productVersion
# Expected output: 26.3 or higher for patched systems

# Check Safari version on macOS
/Applications/Safari.app/Contents/MacOS/Safari --version
# Expected: Safari 26.3 or higher