CVE-2026-22659: Flaskbb

High severity, CVSS 8.1. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Flaskbb Flaskbb: up to and including 2.2.0

Published 2026-07-10. Last modified 2026-07-14.