CVE-2026-86112
BookWyrm through 0.9.1 fails to validate user visibility permissions in the Favorite and Unfavorite views, allowing authenticated attackers to favorite or unfavorite followers-only and direct statuses they cannot access. Attackers can POST to the favorite endpoint with a status ID to create unauthorized interactions, trigger ActivityPub broadcasts, and enumerate private status IDs through response differentiation.
- Published Sep 5, 2026
- CVSS 5.3 medium
- 0.3% chance of exploitation in the next 30 days (EPSS)