CVE-2026-86112
BookWyrm through 0.9.1 Missing Authorization on the Favorite and Unfavorite Endpoints
- State
- Published
- Severity
- 5.3 Medium
- Published
- Sep 5, 2026
- Updated
- Sep 24, 2026
- Reserved
- Sep 5, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 5.4 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N | VulnCheck |
Weaknesses
- CWE-639 Authorization Bypass Through User-Controlled Key
Affected Products
| Product | Versions |
|---|---|
bookwyrmbookwyrm-social |
|
References
- Researcher write-up: finding 2technical-description
- Favorite/Unfavorite fetch by id with no visibility checktechnical-description
- https://github.com/bookwyrm-social/bookwyrmproduct
- VulnCheck Advisory: BookWyrm through 0.9.1 Missing Authorization on the Favorite and Unfavorite Endpointsthird-party-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.