Threat Level Vulnerability Report For a detailed threat advisory, download the pdf file here Summary Apple has released an emergency security update to fix a zero-day vulnerability, CVE-2023-23529, that could be used to hack iPhones, iPads, and Macs. The vulnerability was found in WebKit and could trigger OS crashes, leading to code execution on affected devices. The bug impacts Safari 16.3.1 on macOS Big Sur and Monterey.