DiscordNotifications is an extension for MediaWiki that sends notifications of actions in your Wiki to a Discord channel. DiscordNotifications allows sending requests via curl and file_get_contents to arbitrary URLs set via $wgDiscordIncomingWebhookUrl and $wgDiscordAdditionalIncomingWebhookUrls. This allows for DOS by causing the server to read large files. SSRF is also possible if there are internal unprotected APIs that can be accessed using HTTP POST requests, which could also possibly lead to RCE. This vulnerability is fixed in commit 1f20d850cbcce5b15951c7c6127b87b927a5415e.