CVE-2026-22659
HighCVSS 8.1Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
FlaskBB through version 2.2.0 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.
Risk Assessment
The risk is that moderators can escalate their privileges and manipulate content in forums they do not have access to, potentially leading to unauthorized deletion or hiding of important discussions, compromising platform integrity and trust.
Recommendation
It is recommended to immediately update FlaskBB to a version containing commit acc88cf or later, which fixes this vulnerability. Also review and restrict moderator permissions to the minimum necessary.
Other vulnerabilities in FlaskBB
See all- CVE-2026-46556Medium
Server-Side Request Forgery (SSRF) vulnerability in FlaskBB, a forum software written in Python using Flask. Prior to version 2.2.1, the get_image_info() function allows any authenticated user to force the server to send HTTP requests to arbitrary internal endpoints, including cloud metadata services. This is a blind SSRF with confirmed internal port scanning and internal API triggering capabilities.
- CVE-2026-22660High
FlaskBB through version 2.2.0 contains a logic flaw vulnerability that allows authenticated administrators to delete all built-in authorization groups. The issue is a type mismatch in the bulk AJAX endpoint, where JSON integer group IDs are compared against string literals, causing the protection check to always pass.
Original NVD description (English source)
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.