CVE-2025-23707 is a reflected Cross-site Scripting (XSS) vulnerability classified under CWE-79, found in Matamko's En Masse product versions up to 1.0. The vulnerability stems from improper neutralization of input during web page generation, which allows attackers to inject malicious JavaScript code into web pages viewed by other users. This reflected XSS does not require authentication or elevated privileges but does require user interaction, typically by convincing a user to click a specially crafted URL containing malicious payloads. Once executed in the victim's browser, the injected script can hijack user sessions, steal cookies, manipulate page content, or perform actions on behalf of the user, thereby compromising confidentiality, integrity, and availability of the affected system. The CVSS v3.1 score of 7.1 reflects a high severity due to network attack vector, low attack complexity, no privileges required, but requiring user interaction, and a scope change indicating the vulnerability affects components beyond the initially vulnerable module. No patches or known exploits are currently available, indicating the vulnerability is newly disclosed and unmitigated. The lack of patch links suggests organizations must implement interim mitigations until official fixes are released. The vulnerability's presence in a web-facing product increases the risk of exploitation, especially in environments where En Masse is used for critical business functions or sensitive data handling.

For European organizations, exploitation of this vulnerability could lead to significant data breaches, unauthorized access to sensitive information, and disruption of business operations. Since En Masse is a web-based product, attackers can remotely exploit the vulnerability without authentication, increasing the attack surface. Confidentiality is at risk due to potential session hijacking and data theft, integrity can be compromised by unauthorized actions performed via injected scripts, and availability may be affected if attackers leverage the vulnerability to conduct further attacks such as malware delivery or denial of service. Organizations in sectors such as finance, healthcare, government, and critical infrastructure that rely on En Masse for communication or operational workflows are particularly vulnerable. The reflected XSS also poses risks to end users, potentially damaging organizational reputation and leading to regulatory penalties under GDPR if personal data is compromised.

Organizations should immediately implement strict input validation and output encoding on all user-supplied data within En Masse to prevent script injection. Deploying a robust Content Security Policy (CSP) can help mitigate the impact by restricting the execution of unauthorized scripts. User training to recognize phishing attempts and suspicious links is essential to reduce successful exploitation via social engineering. Network-level protections such as Web Application Firewalls (WAFs) should be configured to detect and block XSS attack patterns targeting En Masse endpoints. Monitoring and logging web traffic for unusual activities can aid in early detection of exploitation attempts. Until an official patch is released by Matamko, consider isolating or limiting access to the En Masse application, especially from untrusted networks. Regularly check for vendor updates and apply patches promptly once available. Additionally, review and harden session management mechanisms to reduce the impact of session hijacking.