Of note: ARM processors are not immune as shown in the article, although official documentation is not available at present. Original side channel issues were reported and recorded in the latter part of 2021, this is the follow on of ongoing research into the mitigation and developer support in that arena.
https://www.digitaltrends.com/computing/hertzbleed-vulnerability-exposes-crypto-keys-on-intel-and-amd/
Intel security advisory SA-00698: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00698.html
Tracked by MITRE as CVE-2022-24436
AMD advisory and CPU listing: https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1038
Intel processor listing: https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/processors-affected-consolidated-product-cpu-model.html
Full Hertzbleed paper, are you affected: https://www.hertzbleed.com/
SA