Has Apple discontinued security updates for 2017 iMac

It may get security updates IF something critical comes up.

Note that this will only apply if it's running macOS 13 Ventura, which is as far as it can go.

Ventura has officially rolled off of the supported OS list, but as it's the most recent 'unsupported' version, it's not beyond the realm of possibility that critical updates may still be released for it.

The machine itself is considered vintage now.

MrHoffman wrote:

Servant of Cats wrote:

Ventura no longer gets the most recent versions of Safari. Ventura's version of Safari is still recent enough that you should have no problem accessing most sites – but if you like, you could install one or more third-party browsers…

macOS 13 Ventura is starting to have certificate problems: Updating the Certificate Trust Store on m… - Apple Community

Ouch!

The last update that included security improvements for MacOS 13 (Ventura) which I believe is what should be on your 2017 iMac was August 20th of this year. That was just 2 months ago making the most recent version number being 13.7.8. We do not if there will be another update.

Ventura no longer gets the most recent versions of Safari. Ventura's version of Safari is still recent enough that you should have no problem accessing most sites – but if you like, you could install one or more third-party browsers.

The current version of Firefox runs on Catalina or later, and Mozilla is even still providing "critical security updates" to an older, somewhat outdated version that runs on Sierra, High Sierra, and Mojave. So Mozilla is likely to provide security updates for versions of Firefox that will run on your iMac for quite some time.

Most other major third-party browsers (Brave, Opera, Chrome, Microsoft Edge for Mac) will also run on Ventura.

Servant of Cats wrote:

Ventura no longer gets the most recent versions of Safari. Ventura's version of Safari is still recent enough that you should have no problem accessing most sites – but if you like, you could install one or more third-party browsers…

macOS 13 Ventura is starting to have certificate problems: Updating the Certificate Trust Store on m… - Apple Community