That’s what this article is telling me. Most of the article was pretty high-tech, and above my understanding, but it sounds somewhat scary. According to the article, a particular type of cable that looks like any other cable “… can capture keystrokes, steal credentials, exfiltrate data, even plant malware—and there’s nothing needed but the cable itself.”
It also discusses malware that can be planted into public USB ports. I was already aware of that and have avoided using USB ports and airports, but it never occurred to me to think of hotels. So from now on, I’m using my own USB ports that I bring, and will refrain from using the ones in the hotel.