The Admin Columns WordPress plugin before 4.3 and Admin Columns Pro WordPress plugin before 5.5.1 do not sanitise and escape its Label settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)

The Admin Columns Free WordPress plugin before 4.3 and Admin Columns Pro WordPress plugin before 5.5.1, rendered input on the posted pages with improper input validation on the value passed into the field 'Label' parameter, by taking this as an advantage an authenticated attacker can supply a crafted arbitrary script and execute it.