Apple has released macOS Sequoia 15.1.1
Apple has just released an update to macOS Sequoia, bringing it to version 15.5.1, build 24B2091. This brings two important security fixes, to JavaScriptCore and WebKit, both of which Apple believes may already have been exploited. The update should be less than 800 MB to download.
Security release notes are here.
Further details as I get them.