Misskey is an open source, federated social media platform. The patch for CVE-2024-52591 did not sufficiently validate the relation between the `id` and `url` fields of ActivityPub objects. An attacker can forge an object where they claim authority in the `url` field even if the specific ActivityPub object type require authority in the `id` field. Version 2025.2.1 addresses the issue.
https://github.com/misskey-dev/misskey/security/advisories/GHSA-6w2c-vf6f-xf26
https://github.com/misskey-dev/misskey/releases/tag/2025.2.1