CVE-2026-28003 is an unauthenticated Cross-Site Scripting (XSS) vulnerability classified under CWE-79 affecting yonifre Maspik – Spam blacklist software versions up to 2.9.1. The flaw arises from improper neutralization of input during web page generation, enabling attackers to inject malicious scripts. The CVSS 3.1 base score is 7.1, reflecting network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability. No vendor advisory or patch information is currently provided.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the affected web application, potentially leading to limited confidentiality, integrity, and availability impacts. Since the vulnerability is unauthenticated, it can be exploited by remote attackers without credentials, but requires user interaction to trigger the malicious script execution.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider applying web application firewall (WAF) rules to detect and block XSS payloads and limit exposure by restricting access to the affected application where feasible.