NextCellent Gallery <= 1.9.35 - Admin+ Stored XSS

The plugin does not sanitise and escape some of its image settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks when the unfiltered_html capability is disallowed (for example in multisite setup)

PoC

Create/edit a gallery with at least one image, put the following payload in the “Alt & Title Text” field: State of Mind"autofocus onfocus=alert(/XSS/)// Save the changes (via the button next to the Apply button). The XSS will be triggered when editing the Gallery again