Vulnerability · Published Jul 10, 2026 · Assigned by VulnCheck

CVE-2026-22659FlaskBB Authorization Bypass via Topic ID Manipulation

High 8.1

In plain English

A high-severity incorrect authorization in flaskbb from flaskbb. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.5%top 55.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
flaskbb	flaskbb	0 – through 2.2.0

Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

References

GitHub Security Advisory (GHSA-9rjj-9p2h-6c55) vendor-advisory
Patch Commit patch
https://www.vulncheck.com/advisories/flaskbb-authorization-bypass-via-topic-id-manipulation third-party-advisory