CVE-2026-39781: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Dan Rossiter Document Gallery

This vulnerability, identified as CWE-79, involves improper neutralization of input during web page generation in Document Gallery versions up to 5.1.1. It allows unauthenticated attackers to perform Cross-Site Scripting (XSS) attacks, potentially executing arbitrary scripts in the context of the affected web application. 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 scope changed. The impacts include low confidentiality, integrity, and availability impacts.

Successful exploitation of this vulnerability can allow an attacker to execute arbitrary scripts in the victim's browser, potentially leading to partial disclosure of information, modification of data, or disruption of service within the scope of the affected application. The vulnerability does not require authentication, increasing its risk. However, user interaction is required for exploitation.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is provided at this time. Until a patch is available, consider applying web application firewall (WAF) rules to detect and block XSS payloads and review input validation and output encoding practices in the affected application.