This flaw does not exist. This researcher falsely claims that a corrupted Telegram sticker could be used as an attack vector — which completely disregards that all stickers uploaded to Telegram are validated by its servers before they can be played by Telegram apps.

× Ad placement — ad format: Message in Channel or Banner in Video;
× Target countries — countries where the ad will be shown. One country must be selected;
× Target locations — specific cities or locations within selected country;
× Target user languages — user languages;
× Target topics — interest topics for ad targeting;
× Only target users interested in all selected topics — separate toggle that shows ads only to users who match all selected topics at once;
× Target channel audiences — lets you choose channel audiences to target;
× Target device type — All devices, iOS, Android, Mobile, or Desktop;
× Show this ad in channels related to Politics & Incidents only — separate toggle to show ads only in channels related to this category;
× Exclude topics — topic exclusions;
× Exclude channel audiences — exclusions by audiences of specific channels;
× Do not show this ad in channels related to Politics & Incidents — separate toggle to fully exclude this channel category.

This label is shown on users of the russian Telegram client, which is not safe to use.