That’s always possible, but I don’t think the evidence bears it out. When Apple releases a new version of macOS 26 with a bunch of security fixes, a great many of those are also addressed in macOS 15 and macOS 14, showing that they’re in core code that has been around for years. And we know that Apple doesn’t always backpatch everything it fixes in the latest version, so there may be more vulnerabilities in the older operating systems that Apple knows about but doesn’t consider severe enough to risk patching.
Since Apple very seldom goes back more than two versions for macOS, and only updates older versions of iOS/iPadOS for truly serious bugs that are being exploited, it seems safe to me to assume that older operating systems are vulnerable.
Although I haven’t established a blanket ban yet, the general consensus is against paste-bombing with AI responses. The fact that you pushed the AI to get the answer you wanted is part of the issue, because they’ll happily support any position you want and then argue the exact opposite if you ask them to. @silbey’s responses (which were roughly along the lines of what I would have written) show just how tenuous the pushed AI responses are.
We discussed that at length here:
I’m not going to delete this since, for the moment, it seems like a constructive conversation on a topic where others may also believe that older operating systems are somehow more secure, but I am going to move it to a separate topic.