CVE-2026-28228 is a high-severity vulnerability affecting Frentix OpenOlat, an open-source web-based e-learning platform. This vulnerability allows authenticated users with the Author role to inject Velocity directives into reminder email templates, which are evaluated server-side when processed. Leveraging this flaw, an attacker can instantiate arbitrary Java classes, including the java.lang.ProcessBuilder, enabling the execution of operating system commands with the privileges of the Tomcat process, typically root in containerized deployments. This issue has been addressed in versions 19.1.31, 20.1.18, and 20.2.5, underscoring the importance of timely patching.
Given the CVSS score of 8.8, this vulnerability is categorized as high severity, indicating significant potential impact to affected organizations. The ability for attackers to execute commands on the server poses a severe risk to confidentiality, integrity, and availability of the system. Organizations utilizing OpenOlat should prioritize addressing this vulnerability in their patch management cycle.
As of the last update, there is no known public exploit for CVE-2026-28228, but the nature of the vulnerability warrants immediate attention. Organizations must not only patch the software but also consider implementing additional security measures to mitigate risks associated with potential exploitation.
Organizations should prioritize patching immediately to safeguard against this vulnerability, ensuring that their instances of OpenOlat are updated to the latest versions.
The exploitation status of this vulnerability remains critical, as it could lead to unauthorized access and control of affected systems. Cybersecurity teams must remain vigilant and proactive.
Vulnerability Details
The official description of CVE-2026-28228 states that this vulnerability allows authenticated users with the Author role to exploit the system by injecting malicious directives into email templates. The affected versions include those prior to 19.1.31, 20.1.18, and 20.2.5. The issue has been classified under CWE-1336, indicating inadequate input validation and sanitization practices.
The CVSS score of 8.8 signifies a high risk associated with this vulnerability, highlighting its potential to cause significant damage if exploited. The vulnerability is characterized by a network attack vector, low complexity, and requires low privileges, making it accessible for potential attackers.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of user inputs within the email reminder template system. Attackers may leverage this flaw by chaining Velocity's #set directive with Java reflection to execute arbitrary code. The attack vector is network-based, allowing exploitation without physical access to the server.
Attack complexity is deemed low, as the attacker requires only low privileges to initiate the exploit. No user interaction is necessary, further enhancing the exploitability of this vulnerability. The impacts on confidentiality, integrity, and availability are all classified as high, indicating severe potential consequences for organizations.
Risk & Impact Analysis
Risk to organizations includes unauthorized access and execution of commands on affected systems, potentially leading to data breaches or service disruptions. The blast radius for this vulnerability is significant, considering the potential for exploitation in environments where OpenOlat is deployed, particularly if sensitive information is processed or stored.
Given the CVSS score and the nature of this vulnerability, organizations should assess their exposure and prioritize remediation efforts. The urgency is underscored by the potentially severe consequences of exploitation.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of OpenOlat include all versions prior to 19.1.31, 20.1.18, and 20.2.5. Organizations running these versions are strongly urged to upgrade to the latest patched versions to mitigate this vulnerability.
Mitigation & Remediation
To mitigate this vulnerability, organizations should apply the available patches provided by Frentix in versions 19.1.31, 20.1.18, and 20.2.5. If immediate patching is not feasible, organizations should consider implementing configuration hardening measures, such as restricting access to email reminder functionalities, and monitoring server logs for suspicious activities.
For a comprehensive approach to security, organizations may also consider conducting regular security assessments and engaging in penetration testing to identify and remediate similar vulnerabilities proactively.
Detection Guidance
Organizations should monitor their server logs for indicators of exploitation attempts, such as unusual patterns in email processing or unexpected Java exceptions. Behavioral anomalies in system operations may also signal potential exploitation of this vulnerability.
AppSecure Threat Intelligence Insight
The significance of CVE-2026-28228 reflects broader trends in web application security, particularly concerning the risks associated with template injection vulnerabilities. Organizations must recognize the importance of secure coding practices and proper input validation to mitigate such risks effectively.
Security teams should stay informed about potential vulnerabilities and implement proactive security measures to safeguard their applications. For further reading on web application security best practices, refer to our web application penetration testing guide.
Additionally, organizations should consider integrating security testing frameworks into their development lifecycle to enhance their overall security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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