CVE-2026-81778: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in The4 Kalles Addons

This vulnerability, identified as CVE-2026-81778, is a CWE-79 type cross-site scripting flaw in The4's Kalles Addons product. It affects versions up to and including 1.0.6. The issue arises from improper neutralization of input during web page generation, which could allow an authenticated subscriber with limited privileges to execute arbitrary scripts in the context of the affected web application. The CVSS 3.1 vector indicates network attack vector, low attack complexity, requiring privileges and user interaction, with a scope change and low impact on confidentiality, integrity, and availability.

Successful exploitation could allow an attacker with subscriber-level access to execute arbitrary scripts in the victim's browser, potentially leading to session hijacking, information disclosure, or other client-side impacts. The overall impact is rated medium due to the requirement for user interaction and privileges.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider restricting subscriber input or applying web application firewall (WAF) rules to detect and block malicious payloads related to XSS. Monitor vendor channels for updates.