CVE-2026-102584 in Moodle
Summary
by MITRE • 09/30/2026
A flaw was found in Moodle. Due to a missing capability check, a low-privileged authenticated user can trigger the recalculation of grade penalties without holding the required permissions. This issue allows unauthorized users to modify grade penalty records, potentially altering student assessment scores.
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Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified within the Moodle learning management system represents a critical failure in access control mechanisms, specifically categorized under CWE-284 Improper Access Control. The core technical flaw stems from an insufficient verification of user privileges during the execution of grade penalty recalculation functions. In a properly secured environment, any operation that modifies sensitive academic data such as student assessment scores must be gated by strict capability checks to ensure only authorized personnel with specific roles like teachers or administrators can perform these actions. However, in this instance, the application logic fails to validate whether the authenticated user possesses the necessary permissions before proceeding with the recalculation process. This oversight allows any low-privileged authenticated user who has valid login credentials for the system to bypass security controls and execute administrative-level operations intended exclusively for higher-privilege accounts.
From an operational perspective, this vulnerability poses a severe threat to the integrity of academic records and institutional trust. By exploiting this flaw, attackers can manipulate grade penalty records without detection through standard audit logs that might not distinguish between legitimate administrative actions and unauthorized modifications triggered by lower-tier users. The ability to alter student assessment scores directly impacts fairness in education, potentially leading to unjustified grade inflation or deflation for students. This manipulation undermines the reliability of academic transcripts and certification processes, which are foundational to educational institutions' credibility. Furthermore, such unauthorized changes can have long-term consequences on students who rely on accurate grading for university admissions, scholarship eligibility, or professional licensing requirements where GPA is a determining factor.
The attack vector associated with this vulnerability aligns closely with MITRE ATT&CK techniques related to privilege escalation and data manipulation by authenticated users. Specifically, it reflects patterns seen in lateral movement within internal systems where an attacker leverages existing valid credentials to perform actions beyond their assigned role boundaries. Since the exploit requires only authentication rather than complex exploitation of memory corruption or remote code execution flaws, the barrier to entry for malicious actors is significantly lowered. This makes the vulnerability particularly dangerous as it can be exploited by insiders with minimal access rights or external attackers who have obtained compromised user credentials through phishing or credential stuffing attacks. The simplicity of triggering the recalculation function means that automated tools could potentially scan multiple instances rapidly if exposed, amplifying the scale of potential damage across educational networks.
To mitigate this risk, immediate remediation efforts should focus on implementing robust server-side validation for all grade-related operations. Developers must ensure that every endpoint involved in modifying academic data performs a comprehensive check against the user's role and associated capabilities before processing any requests. This includes verifying not just general authentication status but specific permissions tied to grade management tasks such as editing penalties, adjusting scores, or recalculating final grades. Additionally, enhancing audit logging mechanisms is crucial for detecting anomalous activity patterns that may indicate exploitation attempts. Institutions should also consider implementing role-based access control policies that adhere to the principle of least privilege, ensuring users are granted only the minimum permissions necessary for their specific functions. Regular security audits and penetration testing focused on access control flaws will help identify similar gaps in other modules before they can be exploited by adversaries seeking to compromise academic integrity.