CVE-2026-43716: Safari Memory Handling Vulnerability – Denial of Service Risk

Technical summary

CVE-2026-43716 is a memory safety vulnerability affecting Safari and Apple's mobile and desktop operating systems. The vulnerability stems from improper memory handling (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer, and CWE-416: Use After Free) that allows malicious web content to trigger an unexpected application crash. The flaw requires user interaction (visiting a malicious site) but no authentication or special privileges. The CVSS 3.1 score of 6.5 (Medium) reflects a high availability impact with no confidentiality or integrity consequences.

Business impact

For organizations where employees use Safari or Apple devices, this vulnerability poses a denial-of-service risk. Compromised websites or attacker-controlled domains could systematically crash Safari sessions, degrading user productivity. However, the impact is localized to browser availability; no data exfiltration or lateral movement is possible through this vector alone. Security teams should weigh the disruption cost against the absence of data breach risk when prioritizing remediation.

Affected systems

Safari (version before 26.5.2), iOS (before 26.5.2), iPadOS (before 26.5.2), and macOS Tahoe (before 26.5.2) are affected. This covers a broad range of Apple devices: all iPhones, iPads, and Mac computers running vulnerable versions. Enterprise environments with mandated Apple device use are most exposed.

Exploitability

Exploitation requires user interaction (clicking a link or visiting a malicious site) but is otherwise straightforward—no special network access, authentication, or user privileges are needed. The attacker simply hosts crafted web content and waits for users to visit. However, the vulnerability is not currently tracked in the CISA Known Exploited Vulnerabilities (KEV) catalog, suggesting active exploitation in the wild is not yet confirmed at publication.

Remediation

Apply patches immediately to Safari 26.5.2, iOS 26.5.2, iPadOS 26.5.2, and macOS Tahoe 26.5.2 or later. For organizations managing Apple devices, use mobile device management (MDM) solutions to enforce automatic updates. As an interim measure, restrict browser access to untrusted domains or educate users to avoid clicking suspicious links.

Patch guidance

Update Safari to 26.5.2 or later via the App Store or system updates. On iOS and iPadOS, navigate to Settings > General > Software Update and install version 26.5.2 or newer. On macOS, use System Preferences > Software Update to install Tahoe 26.5.2 or later. Verify patch deployment through MDM tools or by checking Safari's About menu (Safari > About Safari) to confirm the running version matches or exceeds the patched version.

Detection guidance

Monitor for Safari crashes in your environment using endpoint detection and response (EDR) tools or system logs. Look for unexpected Safari process terminations correlated with web browsing activity. Web gateway or proxy logs may reveal patterns of users visiting previously unknown or suspicious domains. Internal security teams should also track patch compliance rates for the affected platforms to identify unpatched systems.

Why prioritize this

Although the CVSS score is Medium and there is no evidence of active exploitation, the vulnerability affects a popular consumer and enterprise browser used across many Apple devices. The low barrier to exploitation (user interaction only) and wide user base warrant prompt patching. Organizations with high Apple device adoption should treat this as moderate priority; those with minimal Safari use in their environment may defer patching to routine update cycles.

Risk score, explained

The CVSS 3.1 score of 6.5 reflects the combination of network accessibility (AV:N), low attack complexity (AC:L), no required privileges (PR:N), but required user interaction (UI:R). The high availability impact (A:H) from a crash is offset by the absence of confidentiality or integrity impact. The score appropriately captures a disruptive but not data-compromising vulnerability. Organizations may assign higher internal risk depending on Safari's criticality in their environment.

Frequently asked questions