CVE-2025-11699 identifies a critical session management vulnerability in nopSolutions' nopCommerce e-commerce platform, specifically affecting versions up to 4.70 and version 4.80.3. The core issue is that the application fails to invalidate session cookies upon user logout or session termination, violating secure session handling best practices. This flaw allows an attacker who has obtained a valid session cookie—potentially through network interception, XSS, or other means—to reuse that cookie to access privileged endpoints such as the /admin interface, even after the legitimate user has logged out. This effectively enables session hijacking and unauthorized administrative access, compromising confidentiality and integrity of the e-commerce platform. The vulnerability is classified under CWE-613 (Insufficient Session Expiration), highlighting the failure to properly expire or revoke session tokens. nopCommerce versions above 4.70, excluding 4.80.3, have implemented fixes to properly invalidate sessions upon logout. No public exploits have been reported yet, but the vulnerability presents a significant risk if exploited. The lack of a CVSS score necessitates a severity assessment based on impact and exploitability factors. Given the ease of exploitation once a session cookie is obtained and the high-value targets involved, this vulnerability poses a high risk to affected deployments.

For European organizations operating e-commerce platforms using affected nopCommerce versions, this vulnerability can lead to unauthorized administrative access, allowing attackers to manipulate product listings, customer data, orders, and potentially deploy further malicious actions such as data exfiltration or ransomware. The compromise of administrative sessions undermines the confidentiality, integrity, and availability of the e-commerce system. This can result in financial losses, reputational damage, regulatory penalties under GDPR for data breaches, and disruption of business operations. Since nopCommerce is widely used among small to medium enterprises in Europe, the risk is amplified in countries with high e-commerce adoption. Attackers do not require user interaction beyond possession of a valid session cookie, which can be obtained through other attack vectors, increasing the threat surface. The persistence of session tokens post-logout also complicates incident response and detection.

European organizations should immediately verify their nopCommerce version and upgrade to a version above 4.70 that is not 4.80.3, where the vulnerability is fixed. If upgrading is not immediately possible, implement compensating controls such as enforcing short session timeouts, monitoring for anomalous session reuse, and deploying web application firewalls (WAFs) to detect suspicious access patterns to administrative endpoints. Additionally, organizations should review session management policies to ensure session tokens are invalidated server-side upon logout or session expiration. Implement multi-factor authentication (MFA) for administrative access to reduce the impact of session hijacking. Regularly audit logs for unauthorized access attempts and educate users about secure session handling. Network-level protections such as TLS encryption and secure cookie flags (HttpOnly, Secure, SameSite) should be enforced to reduce session token theft risks.