Reddit: XSS in redditmedia.com can compromise data of reddit.com

Description Hi, i would like to report a XSS in redditmedia.com that can affect the reddit.com application. In redditmedia.com domain we are in the domain that reddit.com use to get all the thumbmails of any post. I found that redditmedia.com/gtm/jail uses the "id" parameter to get a valid GTM id...