CVE-2026-22659 FlaskBB Authorization Bypass via Topic ID Manipulation
Authenticated moderators can bypass permission checks to modify topics in forums they do not control by manipulating topic IDs in batch requests.
- 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-2026-22659?
CVE-2026-22659 is a high-severity missing authorization vulnerability in flaskbb, published on 10 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
FlaskBB through 2.2.0, fixed in commit acc88cf, contains an authorization bypass vulnerability that allows authenticated moderators to perform unauthorized actions on topics in forums they do not control by submitting crafted topic ID lists. Attackers can include a low-ID topic from a permitted forum as an anchor in a batch request, causing the permission check applied only to the first result to pass, and then execute lock, unlock, delete, or hide actions against topics in unmoderated forums.
Weakness: CWE-863
Which versions are affected by CVE-2026-22659?
How do I fix CVE-2026-22659?
No fix has been published for CVE-2026-22659 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-2026-22659 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22659 exists.
Sources
Also known as GHSA-9rjj-9p2h-6c55.