Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Liquid Web / StellarWP Gutenberg Blocks by… (CVE-2026-103354)

CVE-2026-103354 describes a stored cross-site scripting (XSS) vulnerability in the Gutenberg Blocks by Kadence Blocks plugin, specifically in versions up to 3.7.11.1. The issue arises from improper neutralization of input during web page generation, which can allow an attacker to inject malicious scripts that persist and execute in the context of users viewing the affected pages. The CVSS 3.1 base score is 7.1, indicating a high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of users who view the affected content, potentially leading to data theft, session hijacking, or other malicious actions impacting confidentiality, integrity, and availability of the affected system.

No patch or official fix information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting user input that can be rendered by the plugin or applying web application firewall (WAF) rules to detect and block XSS payloads.