What the vulnerability does
01Description
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Ultimate Blocks Ultimate Blocks ultimate-blocks allows Stored XSS.This issue affects Ultimate Blocks: from n/a through <= 3.3.6.
Explanation of Vulnerability in Simple Terms
02Summary
Ultimate Blocks versions 3.3.6 and earlier contain a stored cross-site scripting (XSS) vulnerability. An authenticated user with low privileges can inject malicious scripts that execute in the browsers of other site visitors, including administrators. The vulnerability requires user interaction to trigger and can affect multiple users across the site.
What an attacker can do
03Attacker Capabilities
Inject malicious scripts that run in other users' browsers when they view affected content.
Potential impact on your site
04Site Impact
Attackers with contributor or subscriber access can compromise admin accounts, steal data, or modify site content via stored XSS.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege account on the site; victim must view the page containing the injected script.
Key dates
06Disclosure timeline
October 22, 2025
CVE published
April 28, 2026
Record updated