About Apple security updates
For our customers' protection, Apple doesn't disclose, discuss, or confirm security issues until an investigation has occurred and patches or releases are available. Recent releases are listed on the Apple security updates page.
Apple security documents reference vulnerabilities by CVE-ID when possible.
For more information about security, see the Apple Product Security page.
Released September 13, 2021
Available for: macOS Catalina and macOS Mojave
Impact: Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
Description: A use after free issue was addressed with improved memory management.
CVE-2021-30858: an anonymous researcher
* After installing this update, the build number for Safari 14.1.2 is 146126.96.36.199.7 on macOS Mojave and 156188.8.131.52.7 on macOS Catalina.