CVE-2026-43718: 
Apple Safari vulnerability analysis and mitigation

CVE-2026-43718 is a stack-based buffer overflow vulnerability in Apple's WebRTC component (within WebKit) that can cause an unexpected Safari crash when processing maliciously crafted web content. It was discovered by Nan Wang (@eternalsakura13) and disclosed on June 29, 2026, alongside the release of patches. Affected products include Safari, iOS, iPadOS, and macOS Tahoe — all versions prior to 26.5.2. It carries a CVSS v3.1 base score of 6.5 (Medium) (Apple iOS/iPadOS Advisory, GitHub Advisory).

The vulnerability is classified as CWE-121 (Stack-based Buffer Overflow) and resides in the WebRTC component of WebKit (tracked as WebKit Bugzilla #313350). Insufficient input validation during the processing of web content allows a stack overflow to be triggered when a user visits or is directed to a maliciously crafted webpage. Exploitation requires user interaction — specifically, a victim must process attacker-controlled web content in Safari — but no authentication or special privileges are needed on the attacker's side. The fix was implemented via improved input validation (Apple iOS/iPadOS Advisory, Apple macOS Advisory, Apple Safari Advisory).

Successful exploitation results in an unexpected crash of the Safari browser, constituting a denial-of-service (DoS) impact. There is no reported impact on confidentiality or data integrity — the CVSS scoring reflects high availability impact only, with no confidentiality or integrity loss. The vulnerability affects Safari on macOS Sonoma, macOS Sequoia, macOS Tahoe, iOS, and iPadOS, meaning a broad range of Apple consumer and enterprise devices are within scope (GitHub Advisory, Apple iOS/iPadOS Advisory).

Apple has released patches addressing this vulnerability in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, and macOS Tahoe 26.5.2, all released on June 29, 2026. Users should update their devices immediately via System Settings > General > Software Update (iOS/iPadOS/macOS) or the Mac App Store (Safari on older macOS). Enabling automatic updates is recommended to ensure timely receipt of future security patches. Until patching is complete, users should exercise caution when visiting untrusted websites or following links from unknown sources (Apple iOS/iPadOS Advisory, Apple macOS Advisory, Apple Safari Advisory).

The vulnerability was covered as part of broader reporting on Apple's June 2026 security update cycle, which addressed dozens of vulnerabilities across its platforms. Lifehacker published consumer-facing articles urging iPhone users to update promptly, and the SANS Internet Storm Center noted the update in its diary. The Zero Day Initiative (ZDI) published a review of the June 2026 Apple security updates. No specific researcher commentary or significant controversy regarding this individual CVE was identified (Lifehacker, SANS ISC, ZDI Blog).