CVE-2026-24576 identifies a stored cross-site scripting (XSS) vulnerability in the COP UX Flat product, specifically versions up to 5.4.0. The root cause is improper neutralization of input during web page generation, which allows an attacker to inject malicious scripts that are stored on the server and later executed in the browsers of users who access the affected pages. Stored XSS is particularly dangerous because it does not require user interaction beyond visiting a compromised page, and the malicious payload can persist over time. Exploitation can lead to theft of session cookies, enabling attackers to impersonate users, perform unauthorized actions, or deliver further malware. The vulnerability was published on January 23, 2026, with no CVSS score assigned yet and no known exploits in the wild. The lack of patches at the time of publication suggests that organizations must proactively implement mitigations. The vulnerability affects the UX Flat component of the COP product suite, which is used in web application interfaces. The technical details confirm the issue is related to input handling during dynamic web page generation, a common vector for XSS attacks. Since no authentication or complex user interaction is required, the attack surface is broad. The absence of a CVSS score necessitates an independent severity assessment based on impact and exploitability factors.

For European organizations, exploitation of this stored XSS vulnerability can compromise the confidentiality and integrity of user sessions and data. Attackers could hijack user accounts, escalate privileges, or manipulate application behavior, potentially leading to data breaches or unauthorized transactions. Organizations relying on COP UX Flat for critical web interfaces, including governmental, financial, or healthcare sectors, face increased risk of reputational damage and regulatory penalties under GDPR if personal data is exposed. The persistent nature of stored XSS means that multiple users can be affected over time, amplifying the impact. Additionally, attackers could use the vulnerability as a foothold for further attacks within the network. The lack of known exploits currently reduces immediate risk but does not eliminate the threat, especially as proof-of-concept exploits may emerge. The vulnerability could also be leveraged in targeted attacks against European entities with strategic importance or high-value data.

Organizations should monitor COP vendor communications for official patches and apply them promptly once available. Until patches are released, implement strict input validation on all user-supplied data, ensuring that potentially dangerous characters are sanitized or escaped before rendering. Employ comprehensive output encoding strategies to neutralize scripts in HTML, JavaScript, and other contexts. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. Conduct regular security audits and penetration testing focused on input handling and web application security. Educate developers on secure coding practices to prevent similar vulnerabilities. Additionally, consider using Web Application Firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting COP UX Flat endpoints. Maintain robust logging and monitoring to detect suspicious activities indicative of exploitation attempts.