FlaskBB up to 2.2.0 Topic authorization

Summaryinfo

A vulnerability classified as critical has been found in FlaskBB up to 2.2.0. Impacted is an unknown function of the component Topic Handler. Performing a manipulation results in authorization. This vulnerability is identified as CVE-2026-22659. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, was found in FlaskBB up to 2.2.0. This affects some unknown processing of the component Topic Handler. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-22659 since 01/08/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/10/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-42878). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• FlaskBB

Version

• 2.0
• 2.1
• 2.2.0

Website

• Product: https://github.com/flaskbb/flaskbb/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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