CVE-2025-52750 identifies a reflected Cross-site Scripting (XSS) vulnerability in the Juergen Schulze Emu2 software, specifically in the emu2-email-users-2 component. The flaw stems from improper neutralization of user-supplied input during dynamic web page generation, allowing attackers to inject malicious JavaScript code that executes in the context of the victim’s browser session. This vulnerability affects all versions up to and including 0.83b. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), no privileges (PR:N), but does require user interaction (UI:R), and has a scope change (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. The impact includes partial loss of confidentiality, integrity, and availability (C:L/I:L/A:L), enabling attackers to steal session cookies, manipulate web content, or perform actions on behalf of the user. Although no public exploits are currently known, the vulnerability’s characteristics make it a viable target for phishing campaigns or targeted attacks. The vulnerability was reserved in June 2025 and published in October 2025, with no patches currently linked, indicating a window of exposure. The lack of CWE classification suggests a straightforward XSS issue without complex underlying conditions. Emu2 is a niche product, but its use in certain European sectors could present a significant risk if exploited.

For European organizations, this vulnerability poses a significant risk to web applications relying on Emu2, particularly those handling sensitive user data or authentication sessions. Exploitation can lead to session hijacking, unauthorized actions, data theft, and potential lateral movement within networks if attackers leverage stolen credentials or tokens. The reflected XSS nature means attackers can craft malicious URLs to target users via phishing or social engineering, increasing the risk of widespread compromise. Organizations in sectors such as finance, government, and critical infrastructure that use Emu2-based solutions may face reputational damage, regulatory penalties under GDPR for data breaches, and operational disruptions. The scope change in the CVSS vector indicates that the impact can extend beyond the immediate vulnerable component, potentially affecting other integrated systems or services. The absence of known exploits currently provides a limited window for proactive mitigation before active exploitation emerges.

1. Monitor official channels for patches or updates from Juergen Schulze and apply them promptly once available. 2. Implement strict input validation and output encoding on all user-supplied data to prevent script injection, using context-aware encoding techniques. 3. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. 4. Educate users about the risks of clicking on suspicious links, especially those received via email or untrusted sources, to reduce successful phishing attempts. 5. Employ web application firewalls (WAFs) with rules designed to detect and block reflected XSS payloads targeting Emu2 endpoints. 6. Conduct regular security assessments and penetration testing focused on web application input handling to identify and remediate similar vulnerabilities. 7. Isolate critical Emu2 deployments within segmented network zones to limit potential lateral movement if exploitation occurs. 8. Log and monitor web server and application logs for unusual input patterns or repeated attempts to exploit XSS vectors.