CVE-2025-64633 is a Cross-Site Scripting (XSS) vulnerability identified in colabrio's Norebro Extra product, affecting versions up to and including 1.6.8. The root cause is improper neutralization of script-related HTML tags within web pages generated by the application, which allows attackers to inject malicious scripts. This vulnerability is classified as a basic XSS, meaning that the injected code can execute in the context of the victim's browser without requiring authentication or user interaction. The CVSS v3.1 base score is 5.3 (medium), with vector AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N, indicating network attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, and limited impact on confidentiality only. The vulnerability could enable attackers to steal sensitive information such as session cookies or perform actions on behalf of the user, but it does not allow modification of data or disruption of service. No public exploits or active exploitation in the wild have been reported as of the publication date. The vulnerability was reserved in early November 2025 and published in mid-December 2025. No patches or fixes are currently linked, suggesting that organizations should monitor vendor advisories closely. The lack of CWE identifiers limits detailed classification, but the issue aligns with CWE-79 (Improper Neutralization of Input During Web Page Generation).

For European organizations using colabrio Norebro Extra, this XSS vulnerability poses a risk primarily to confidentiality. Attackers could exploit it to execute arbitrary scripts in users' browsers, potentially leading to session hijacking, theft of sensitive information, or phishing attacks leveraging the trusted application interface. While the vulnerability does not affect data integrity or availability, the compromise of user sessions or leakage of confidential data could have regulatory and reputational consequences, especially under GDPR. Organizations in sectors with high web application usage, such as finance, healthcare, and government, may face increased risk. The ease of exploitation (no authentication or user interaction required) increases the threat level, although the medium CVSS score reflects the limited scope of impact. Since no known exploits are active, the immediate risk is moderate but could escalate if exploit code becomes available. Failure to address this vulnerability could lead to targeted attacks against European users of the affected software.

1. Monitor colabrio vendor communications for official patches addressing CVE-2025-64633 and apply them promptly once released. 2. Implement strict input validation on all user-supplied data to ensure that script-related HTML tags are properly sanitized or escaped before rendering. 3. Employ robust output encoding techniques, such as HTML entity encoding, to neutralize potentially malicious content. 4. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. 5. Conduct regular security assessments and penetration testing focused on web application vulnerabilities to detect similar issues proactively. 6. Educate developers on secure coding practices related to input handling and output encoding to prevent recurrence. 7. Use web application firewalls (WAFs) with rules tuned to detect and block XSS attack patterns targeting Norebro Extra. 8. Limit exposure by restricting access to the affected application to trusted networks or VPNs where feasible. 9. Monitor logs and user activity for signs of exploitation attempts or anomalous behavior related to web sessions.