The Core i9-12900K has already been seen at 6.8 GHz, well beyond its stock boost clock speed. Someone has overclocked the chip to even higher speeds though, with 7.5 GHz now not that far away.
https://www.notebookcheck.net/The-Intel-Core-i9-12900K-scales-crazy-heights-with-a-new-extreme-overclocking-result.576138.0.html