CVE-2025-13935 is a vulnerability classified under CWE-862 (Missing Authorization) found in the Tutor LMS plugin for WordPress, versions up to and including 3.9.2. The flaw resides in the 'mark_course_complete' function, which lacks proper enrollment verification before allowing a user to mark a course as completed. This means that any authenticated user with subscriber-level permissions or higher can manipulate course completion status without actually completing the course or being enrolled. The vulnerability does not require user interaction beyond authentication and can be exploited remotely over the network. The CVSS v3.1 base score is 4.3, indicating a medium severity level, with the vector AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N, meaning the attack vector is network-based, requires low attack complexity, privileges at the level of a subscriber, no user interaction, unchanged scope, no confidentiality or availability impact, but partial integrity impact. No patches or fixes have been released at the time of publication, and no known exploits are reported in the wild. The vulnerability primarily threatens the integrity of course completion data, potentially undermining the trustworthiness of eLearning certifications and progress tracking within affected installations.

For European organizations, especially educational institutions, corporate training departments, and eLearning providers using Tutor LMS, this vulnerability can lead to unauthorized course completions. This undermines the integrity of training records, potentially allowing users to fraudulently claim course completion and certifications. Such data integrity issues can affect compliance with training requirements, accreditation standards, and internal policies. While the vulnerability does not expose sensitive data or disrupt service availability, the reputational damage and administrative overhead to verify legitimate completions could be significant. Organizations relying on Tutor LMS for regulated training or professional development may face challenges in audit and compliance processes. Additionally, if attackers combine this vulnerability with social engineering or insider threats, it could facilitate broader misuse of learning management systems in Europe.

Until an official patch is released, European organizations should implement several practical mitigations: 1) Restrict subscriber-level user permissions to trusted individuals only, minimizing the risk of unauthorized course completion. 2) Implement additional enrollment verification controls outside the plugin, such as manual approval workflows or integration with external identity management systems. 3) Monitor and audit course completion logs regularly to detect suspicious or anomalous completion patterns. 4) Disable or limit the use of the 'mark_course_complete' function via custom code or WordPress hooks if feasible. 5) Educate administrators and instructors about the vulnerability and encourage vigilance in verifying course completions. 6) Plan for prompt application of vendor patches once available and test updates in staging environments before production deployment. 7) Consider alternative LMS solutions if the risk is unacceptable and patching is delayed.