Updates for 2017 iMac 21.5 with Ventura 13.7.8?

If you are asking whether there will be an update to let that Mac run something higher than Ventura – like Sonoma, Sequoia, or Tahoe – the answer is almost certainly "No."

In the entire 40+ years since the release of the first Macintosh, I do not think there has ever been a case of Apple going back and retroactively adding support for a new major version of the OS for a Mac that had already hit "the end of the line." It would be very unusual, to say the least, if they were to change that now – within a year of when they plan to release a version of macOS (macOS 27) that will not run on any Intel-based Macs.

As for whether there will be any more bug fix or security updates for Ventura, that is harder to say. Apple recently went all the way back to iOS 12 and macOS Catalina with updates to let iMessages work after next January. But if I'm reading Safari release notes correctly, Ventura no longer receives the latest versions of Safari. (It was getting them before Tahoe came out.)

No one here knows, what Apple might or might not do in the future.

For example: The 2012 Mac mini that we use as a Media Server received a 10.15.8 update on Feb. 2 2026