Advisories for Cargo/Lemmy_server package

2025

Lemmy user purging users or communities or banning users can delete images they didn't upload/exclusively use

An improper uploaded media ownership check can result in inadvertent deletion of media when a user is banned with content removal or purged. This can lead to deletion of media that was not uploaded by the banned/purged user. This also applies to purged communities, in which case all media posted in that community will get deleted without proper ownership check. This is limited to media with an image/* content-type returned …

2024

Any authenticated user may obtain private message details from other users on the same instance

Users can report private messages, even when they're neither sender nor recipient of the message. The API response to creating a private message report contains the private message itself, which means any user can just iterate over message ids to (loudly) obtain all private messages of an instance. A user with instance admin privileges can also abuse this if the private message is removed from the response, as they're able …