What the vulnerability does
01Description
The SlingBlocks – Gutenberg Blocks by FunnelKit (Formerly WooFunnels) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's Countdown block's attributes in all versions up to, and including, 1.6.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Explanation of Vulnerability in Simple Terms
02Summary
SlingBlocks – Gutenberg Blocks by FunnelKit versions up to 1.6.0 contain a stored cross-site scripting (XSS) vulnerability. An authenticated user with low privileges can inject malicious scripts into block content that execute in the browsers of other site visitors and administrators. The vulnerability affects the scope beyond the vulnerable component, potentially compromising site security and user data.
What an attacker can do
03Attacker Capabilities
Inject malicious scripts that run in other users' browsers when they view affected pages.
Potential impact on your site
04Site Impact
Attackers with contributor access can inject scripts that steal admin credentials, modify site content, or compromise visitor data.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege authenticated account (e.g., contributor or editor role).
Key dates
06Disclosure timeline
August 21, 2025
CVE published
April 8, 2026
Record updated
