Apple Fixed Two Actively Exploited Vulnerabilities in macOS 12.3.1 Monterey, But Hasn't Released Updates for Big Sur or Catalina

With the release of macOS Monterey 12.3.1 on Thursday, March 31, Apple addressed two critical vulnerabilities that may have been actively exploited in the wild, but as Intego pointed out this week, Apple left macOS Big Sur and macOS Catalina users vulnerable.
The macOS Monterey 12.3.1 update fixed a pair of security flaws, including an AppleAVD issue that could allow an application to execute arbitrary code with kernel privileges and an Intel Graphics Driver issue that could allow an application