CVE-2025-6290 is a stored cross-site scripting vulnerability in the blakelong Tournament Bracket Generator WordPress plugin, affecting all versions up to 1.0.0. The issue arises from improper neutralization of user-supplied input in the 'bracket' shortcode, allowing authenticated users with contributor or higher privileges to inject arbitrary JavaScript code. This code executes in the context of any user who views the injected page, potentially leading to information disclosure or session hijacking. The vulnerability has a CVSS 3.1 base score of 6.4 (AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N), reflecting network attack vector, low attack complexity, and limited privileges required.

An attacker with contributor-level access or higher can store malicious scripts that execute in other users' browsers when they view the affected pages. This can lead to limited confidentiality and integrity impacts, such as theft of user credentials or manipulation of page content. There is no direct impact on availability. The vulnerability affects all versions up to 1.0.0 of the plugin. No known active exploitation has been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict contributor-level access to trusted users only and consider disabling or removing the Tournament Bracket Generator plugin if possible. Monitor for updates from the vendor regarding patches or official mitigations.