Themeton Spare contains a reflected Cross-site Scripting (CWE-79) vulnerability identified as CVE-2025-31638. This vulnerability occurs due to improper neutralization of input during web page generation, enabling attackers to inject and execute malicious scripts in the context of the victim's browser. It affects Spare versions up to 1.7. 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 can allow an attacker to execute arbitrary scripts in the victim's browser, potentially leading to partial disclosure of sensitive information, modification of data, or disruption of service. The reflected nature means the attack requires user interaction, such as clicking a crafted link. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are currently available. Until a patch is released, users should exercise caution with untrusted input and consider implementing web application firewall (WAF) rules to detect and block reflected XSS attempts if possible.