CVE-2025-11923 is a critical privilege escalation vulnerability identified in the LifterLMS plugin for WordPress, which is widely used for managing eLearning, online courses, and quizzes. The vulnerability stems from improper privilege management (CWE-269) within the plugin’s REST API endpoints. Specifically, the update_item_permissions_check() function fails to adequately verify whether a user is authorized to change their own role. When an authenticated user with at least student-level privileges sends a crafted REST API request to update their roles array, the permission check erroneously returns true, allowing them to escalate their privileges to administrator. Additionally, another endpoint intended for instructors also provides an attack vector. This flaw affects multiple major versions of the plugin, from 3.5.3 through 9.1.0, indicating a long-standing issue across many releases. The vulnerability does not require user interaction but does require authentication, making it exploitable by any logged-in user with minimal privileges. The CVSS 3.1 score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) highlights the ease of remote exploitation over the network, low attack complexity, and the severe impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to WordPress sites using LifterLMS, as attackers can gain full administrative control, potentially leading to site defacement, data theft, or persistent backdoors.

For European organizations, especially educational institutions, training providers, and corporate eLearning platforms relying on WordPress with LifterLMS, this vulnerability presents a severe threat. Unauthorized privilege escalation to administrator level allows attackers to fully control the WordPress environment, including installing malicious plugins, altering course content, stealing sensitive user data, and disrupting service availability. Given the widespread adoption of WordPress and LifterLMS in Europe’s education sector, exploitation could lead to significant reputational damage, regulatory non-compliance (e.g., GDPR breaches due to data exposure), and operational disruption. Attackers could also leverage compromised sites as pivot points for further network intrusions. The vulnerability’s presence across multiple plugin versions increases the likelihood that many European organizations remain exposed, particularly those slow to update or unaware of the risk. The lack of known exploits in the wild currently provides a window for proactive defense but also underscores the urgency of mitigation before active exploitation emerges.

European organizations should immediately audit their WordPress installations to identify if LifterLMS is in use and determine the plugin version. Since no official patches or updates are linked in the provided data, organizations should: 1) Temporarily disable the REST API endpoints related to user role modifications if feasible, using WordPress hooks or firewall rules to block suspicious REST API requests targeting role changes. 2) Restrict access to the WordPress admin and REST API to trusted IP ranges where possible. 3) Implement strict monitoring and alerting on REST API calls that attempt to modify user roles or permissions. 4) Enforce strong authentication and consider multi-factor authentication for all users with elevated privileges. 5) Regularly back up WordPress sites and databases to enable rapid recovery in case of compromise. 6) Engage with the plugin vendor or community to obtain or verify availability of patches and apply them promptly once released. 7) Educate site administrators and users about the risks of privilege escalation and suspicious activity. These targeted measures go beyond generic advice by focusing on the REST API attack surface and role modification vectors specific to this vulnerability.