Webex
Are there any security issues with Webex video conferencing?
Mac Pro, macOS 10.13
Probably, but are they worth worrying about? Probably not. Cisco's Webex is the 800 pound gorilla of teleconferencing.
In terms of potential security vulnerabilities Webex is approximately infinitely better than Zoom.
My recommendation is use it if you must, but uninstall its client software when you no longer require it. That way, if someone should exploit an as-yet-to-be-discovered security hole in the future, Cisco will have a chance to address it before you need to use it again.