CVE-2026-103396 bbs-go through 4.4.6 Incorrect Authorization via /api/admin/user/synccount
Authenticated users with view-only permissions can trigger expensive database operations on the user sync endpoint, causing denial of service.
- 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-2026-103396?
CVE-2026-103396 is a medium-severity missing authorization vulnerability in mlogclub bbs-go, published on 30 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
bbs-go through 4.4.6 contains a permission bypass vulnerability in the AdminMiddleware authorization logic where the read-only dashboard.user.view permission rule matches the /api/admin/user/synccount endpoint before the intended dashboard.user.update rule. Authenticated users with only view permissions can call the synccount endpoint to trigger expensive full-table user recounts and cache invalidations, causing denial of service through repeated concurrent database operations.
Weakness: CWE-863
Which versions are affected by CVE-2026-103396?
How do I fix CVE-2026-103396?
No fix has been published for CVE-2026-103396 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-2026-103396 being exploited?
There is no known exploitation of CVE-2026-103396 in the wild and no public exploit code.
Sources
Also known as GHSA-wr27-gh7c-5q9v.