CVE-2025-11699 identifies a session management vulnerability in nopSolutions' nopCommerce e-commerce platform, specifically affecting versions 4.70 and earlier, as well as version 4.80.3. The core issue is insufficient session expiration (CWE-613), where session cookies remain valid even after a user logs out or the session is terminated. This failure to invalidate session tokens allows an attacker who has acquired a valid session cookie—potentially through interception, theft, or other means—to reuse that cookie to access privileged endpoints such as the administrative interface (/admin). This effectively enables session hijacking, compromising the confidentiality and integrity of the affected system. The vulnerability does not require the attacker to have prior privileges, but user interaction is necessary to obtain a valid session cookie. The CVSS v3.1 score of 7.1 indicates a high severity due to the ease of exploitation over the network (AV:N), low attack complexity (AC:L), and significant impact on integrity (I:H) with limited impact on confidentiality (C:L) and no impact on availability (A:N). Notably, versions above 4.70 except 4.80.3 have resolved this issue, indicating a regression in 4.80.3. No public exploits have been reported yet, but the vulnerability poses a serious risk to e-commerce platforms relying on affected versions.

For European organizations using affected nopCommerce versions, this vulnerability poses a significant risk of unauthorized access to administrative functions and sensitive customer data. Attackers exploiting this flaw can hijack sessions post-logout, bypassing authentication controls and potentially manipulating product listings, order data, or customer information. This can lead to data breaches, financial fraud, reputational damage, and regulatory non-compliance under GDPR due to unauthorized access to personal data. The persistence of session cookies after logout undermines trust in session management and can facilitate lateral movement within the compromised environment. Given the widespread use of nopCommerce among small to medium-sized European e-commerce businesses, the impact could be broad, affecting both online retailers and their customers. The lack of known exploits in the wild currently reduces immediate risk, but the vulnerability's nature makes it a prime target for attackers once exploit code becomes available.

European organizations should immediately verify their nopCommerce version and upgrade to a fixed version above 4.70 that is not 4.80.3. If upgrading is not immediately feasible, implement compensating controls such as enforcing strict session timeout policies, invalidating session cookies server-side upon logout through custom patches or middleware, and monitoring for unusual session reuse patterns. Employ secure cookie attributes (HttpOnly, Secure, SameSite) to reduce cookie theft risks. Additionally, implement multi-factor authentication (MFA) for administrative access to mitigate the impact of session hijacking. Regularly audit session management logs and conduct penetration testing focused on session handling. Educate users and administrators about the risks of session hijacking and encourage immediate logout from sensitive sessions. Finally, monitor threat intelligence feeds for emerging exploits targeting this vulnerability to respond promptly.