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.
CVE ID: CVE-2025-25306
CVSS Base Severity: CRITICAL
CVSS Base Score: 9.3
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
Vendor: misskey-dev
Product: misskey
EPSS Score: 0.02% (probability of being exploited)
EPSS Percentile: 2.71% (scored less or equal to compared to others)
EPSS Date: 2025-04-08 (when was this score calculated)