Some users in our org are not able to see the alerts tab in the repo sidebar. What permisssions or rights are needed to see those?
That indeed sounds like a permissions issue. You might want to check the differences in permissions between a user who can access the alerts and a user who can’t access the alerts. I don’t know the permissions off the top of my head.
Also, if the problem is that one repository lacks the tab, that might be because the feature is disabled.
The GH help page: https://help.github.com/articles/viewing-and-updating-vulnerable-dependencies-in-your-repository/ and https://help.github.com/articles/about-security-alerts-for-vulnerable-dependencies/ .