This site is a great resource for finding communities.
It looks like there are several that are already quite large:
cybersecurity (697 users)
securitynews (587 users)
Please note that for the above links to work, someone on your instance needs to have already subscribed to or searched for the remote community so it populates on your instance. You can search in Communities > All for !securitynews@infosec.pub, as an example, and then the links should work after a few seconds.
infosec.pub is the main Lemmy instance for that
make one if not. make yourself the mod
too lazy. used to solo mod a netsec subreddit and didn’t do anything. the community didn’t like that, lol.
i subscribed to /c/netsec but it hasn’t taken off. just wondering if there were already active communities.