CVE-2026-86112 BookWyrm through 0.9.1 Missing Authorization on the Favorite and Unfavorite Endpoints
Authenticated attackers can favorite or unfavorite private statuses, triggering unauthorized ActivityPub broadcasts and enumerating private status IDs.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-86112?
CVE-2026-86112 is a medium-severity missing authorization vulnerability in bookwyrm-social bookwyrm, published on 5 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-639
Which versions are affected by CVE-2026-86112?
How do I fix CVE-2026-86112?
No fix has been published for CVE-2026-86112 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-86112 being exploited?
There is no known exploitation of CVE-2026-86112 in the wild and no public exploit code.
Sources
Also known as GHSA-6779-9x55-mqpq.