CVE-2026-26045 is a code injection vulnerability identified in Moodle's backup restore functionality. The flaw arises because specially crafted backup files are not properly validated during the restore process. When a malicious backup file is restored, it can trigger unintended execution of arbitrary server-side code on the Moodle server. This vulnerability requires authenticated access with restore privileges, which are typically assigned to privileged users such as administrators or course managers. The vulnerability affects Moodle versions 0, 5.0.0, and 5.1.0. The CVSS 3.1 base score of 7.2 indicates a high severity, with an attack vector of network (remote), low attack complexity, high privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the potential for full server compromise makes this vulnerability critical to address. The lack of proper validation in the backup restore process allows attackers to inject malicious code that the server executes, potentially leading to data theft, service disruption, or further network penetration. The vulnerability was published on February 21, 2026, and is tracked under CVE-2026-26045.

The impact of CVE-2026-26045 is significant for organizations using affected Moodle versions. Successful exploitation can lead to full compromise of the Moodle server, allowing attackers to execute arbitrary code with the privileges of the Moodle service. This can result in unauthorized access to sensitive educational data, modification or deletion of course content, disruption of e-learning services, and potential lateral movement within the organization's network. Given Moodle's widespread use in educational institutions, government agencies, and enterprises worldwide, the vulnerability poses a risk to confidentiality, integrity, and availability of critical learning management systems. The requirement for authenticated privileged access limits the attack surface but does not eliminate risk, especially in environments with weak access controls or insider threats. The absence of known exploits in the wild suggests limited active exploitation currently, but the vulnerability's nature and impact warrant urgent remediation to prevent future attacks.

To mitigate CVE-2026-26045, organizations should: 1) Immediately upgrade Moodle installations to patched versions once available from official sources, as no patch links are currently provided but monitoring for updates is critical. 2) Restrict backup restore permissions strictly to trusted administrators and minimize the number of users with such privileges. 3) Implement strong authentication mechanisms, including multi-factor authentication, to reduce risk of credential compromise. 4) Monitor logs for unusual restore activities or attempts to upload backup files from untrusted sources. 5) Employ network segmentation to isolate Moodle servers and limit exposure to internal threats. 6) Conduct regular security audits and vulnerability assessments on Moodle deployments. 7) Educate administrators on the risks of restoring backups from unverified sources. 8) Consider deploying web application firewalls (WAFs) with custom rules to detect anomalous restore requests. These measures combined will reduce the likelihood of exploitation and limit potential damage.