CVE-2026-42163 in Mahara
Summary
by MITRE • 08/18/2026
Mahara before 25.04.5 and 26.04.0 is vulnerable to unauthorized access to internal accounts via Learning Tools Interoperability (LTI) under certain circumstances. This applies to LTI 1.1 and LTI 1.3 Advantage.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/18/2026
The Mahara learning management system, specifically versions prior to 25.04.5 and the initial release of version 26.04.0, contains a critical security flaw within its implementation of the Learning Tools Interoperability protocol. This vulnerability allows for unauthorized access to internal accounts by exploiting weaknesses in how LTI requests are validated and processed. The issue affects both the older LTI 1.1 standard and the newer LTI 1.3 Advantage specification, indicating that the root cause lies in fundamental logic errors rather than a deficiency specific to one protocol version. This broad impact underscores the severity of the oversight in the authentication and authorization mechanisms governing external tool integrations within the platform.
At its core, this vulnerability stems from improper validation of LTI launch requests. When an external learning tool initiates communication with Mahara via LTI, it sends a request containing various parameters intended to authenticate the user and establish their role or permissions. In vulnerable versions, the system fails to adequately verify certain critical attributes within these requests under specific circumstances. This failure permits attackers who can manipulate or forge LTI launch messages to bypass standard access controls. By crafting maliciously formatted requests that exploit gaps in parameter validation, an attacker can impersonate legitimate users or escalate privileges without possessing valid credentials for those internal accounts.
The operational impact of this flaw is significant, as it directly compromises the confidentiality and integrity of user data within the educational environment. An adversary with network access to trigger LTI launches could gain unauthorized entry into Mahara instances, potentially accessing sensitive student information, grades, course materials, or administrative settings depending on the privileges associated with the compromised account. This breach not only violates privacy regulations such as FERPA or GDPR but also undermines trust in the platform among educational institutions and students. Furthermore, because LTI is commonly used to integrate third-party tools like quizzes, video conferencing, and plagiarism checkers, this vulnerability could serve as an entry point for broader attacks against connected systems if those integrations are configured with elevated permissions.
From a classification perspective, this issue aligns closely with CWE-287, which describes Improper Authentication, specifically where the system fails to correctly verify identity before granting access. It also relates to CWE-345, Insufficient Verification of Data Authenticity, as the flaw involves accepting potentially forged or manipulated LTI parameters without rigorous validation. In terms of adversary tactics, this vulnerability facilitates techniques associated with MITRE ATT&CK ID T1078, Valid Accounts, where attackers use legitimate credentials or impersonate valid users to maintain persistence and move laterally within a network. The ability to bypass authentication through protocol manipulation highlights the risks inherent in complex integration standards when implementation details are not rigorously audited for edge cases and malformed inputs.
To mitigate this risk, organizations running Mahara must immediately upgrade to version 25.04.5 or later, which includes patches addressing these validation gaps. For those unable to update instantly due to operational constraints, implementing strict input filtering on LTI parameters at the network perimeter using Web Application Firewalls may provide temporary relief by blocking known malicious patterns associated with this exploit vector. Additionally, administrators should review their LTI configuration settings to ensure that only trusted external tools are permitted and that callback URLs are strictly whitelisted. Regular security audits of integration points and monitoring for anomalous login attempts originating from unexpected IP addresses or user agents can further enhance detection capabilities. Ultimately, ensuring timely patch management is the most effective defense against this type of protocol-level authentication bypass vulnerability.