[TheDauthi]

Try to avoid using it until the microcode fix in a week or two. If you bought it last week, you probably haven't used it enough to permanently damage anything from the voltage issue yet.

Keep careful watch of problems in the future: the oxidation issue for the 13th gen is a physical defect not fixable by the microcode update, but we don't know how widespread it is yet (and Intel is keeping mum). If possible, it might well be worth returning and getting a 14th gen chip, which doesn't suffer from the latter problem and the former will be fixed by microcode.

[Waterluvian]

Is there a safety issue like fire or just a “I need to buy a new CPU” issue?

[TheDauthi]

No known safety issue. Both issues (the overvoltage in both 13 and 14 gen chips, and the oxidation that's limited to 13th gen) lead to system instability. How quickly these occur is unknown from the Intel reports. Claims are as little as a few weeks, but independent verification is needed on that one.

[qingcharles]

No fire. It just ruins some of the micro-electronics inside so that it won't run reliably (or at all).