CVE-2025-11437 is a Cross Site Scripting (XSS) vulnerability affecting JhumanJ OpnForm versions 1.9.0 through 1.9.3. The vulnerability resides in an unspecified part of the /api/open/forms/ endpoint within the Form Editor component. This flaw allows remote attackers to inject malicious scripts that execute in the context of a victim's browser when they interact with the affected forms. The attack vector does not require authentication but does require user interaction, such as clicking a malicious link or visiting a compromised page. The vulnerability can compromise confidentiality by stealing session tokens or other sensitive data accessible via the browser, and integrity by manipulating displayed content. Availability impact is minimal. The vendor has temporarily disabled the vulnerable feature until users configure their own domain, which mitigates the attack surface. Although exploit code has been published, no active exploitation in the wild has been reported. The CVSS 4.0 base score is 4.8 (medium), reflecting network attack vector, low attack complexity, no privileges required, but requiring user interaction and limited impact on confidentiality and integrity. The vulnerability is under review for further handling, and no patches have been officially released yet.

For European organizations using JhumanJ OpnForm, this vulnerability poses a moderate risk primarily to confidentiality and integrity of user sessions and data accessed via the browser. Attackers could exploit the XSS flaw to execute malicious scripts, potentially leading to session hijacking, credential theft, or defacement of web content. This could undermine trust in affected services and lead to data breaches or regulatory non-compliance under GDPR if personal data is exposed. The requirement for user interaction limits large-scale automated exploitation but targeted phishing or social engineering attacks remain feasible. Organizations relying on OpnForm for critical customer-facing forms or internal workflows may experience reputational damage and operational disruption. The temporary disabling of the vulnerable feature reduces immediate risk, but organizations that have configured custom domains and re-enabled the feature remain exposed. The lack of a patch means organizations must rely on mitigations until updates are available.

1. Ensure the vulnerable feature in OpnForm is disabled until a secure configuration is applied, as recommended by the vendor. 2. Monitor vendor communications closely for official patches or updates and apply them promptly once released. 3. Implement strict input validation and sanitization on all user-supplied data in forms to prevent script injection. 4. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 5. Educate users about the risks of interacting with suspicious links or content that could trigger XSS attacks. 6. Conduct regular security assessments and penetration testing focused on web application vulnerabilities, including XSS. 7. Use web application firewalls (WAFs) with rules tuned to detect and block XSS attack patterns targeting the /api/open/forms/ endpoint. 8. Review and restrict permissions for the OpnForm application to minimize potential damage from exploitation. 9. Log and monitor access to the vulnerable endpoint for unusual activity that may indicate exploitation attempts.