CVE-2026-42164 in Mahara
Summary
by MITRE • 08/18/2026
Mahara before 25.04.5 and 26.04.0 is vulnerable in the Text block/section functionality when a call is crafted in a certain way that allows it to recall the backed-up content from another Text section.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified within Mahara versions prior to 25.04.5 and version 26.04.0 represents a significant flaw in how the platform handles data retrieval during backup restoration operations, specifically targeting the Text block functionality. This issue stems from an improper validation of context identifiers when reconstructing content that has been exported and subsequently imported back into the system. When an administrator or user with appropriate privileges initiates a restore process for a site containing text blocks, the application fails to strictly isolate the restored data within its intended scope. Instead, the logic governing the restoration mechanism allows crafted calls to reference backed-up content from one Text section and inject it into another unrelated section. This behavior indicates that the system does not adequately enforce boundary checks between different instances of similar content types during the import phase, leading to a breach in logical isolation.
From a technical perspective, this flaw is classified as an Insecure Direct Object Reference or more specifically, a Cross-Site Request Forgery variant depending on the attack vector, but it aligns closely with CWE-20 Improper Input Validation and CWE-913 Control of Command From Incorrectly Controlled Search Pattern. The core issue lies in the server-side processing of backup archives where identifiers for text sections are not sufficiently sanitized or verified against the current user's permissions and the specific context of the target section. An attacker who can influence the content of a backup file, either by compromising an existing account with export privileges or through social engineering to trick an administrator into importing a maliciously crafted archive, can exploit this logic error. By manipulating the internal references within the XML structure of the Mahara backup file, it is possible to force the application to pull data from a source section that may contain sensitive information and place it into a destination section visible to unauthorized users or in a context where such content should not appear.
The operational impact of this vulnerability extends beyond simple data leakage. It undermines the integrity of educational portfolios and collaborative spaces managed by Mahara, which is widely used in academic institutions for e-portfolio management. If an attacker can inject content from one section into another, they could potentially display sensitive student information, private reflections, or confidential institutional documents to unintended audiences. This constitutes a serious confidentiality breach and also poses risks to data integrity if the injected content includes malicious scripts that execute upon viewing, although the primary vector described focuses on unauthorized access to backed-up text. The ability to cross-reference sections means that privacy controls enforced at the section level are effectively bypassed during the restoration process, rendering those controls ineffective for any site undergoing backup and restore operations.
This vulnerability maps directly to MITRE ATT&CK technique T1530 Data from Cloud Storage Object or more accurately in this context, it relates to data exfiltration via improper access control mechanisms similar to T1078 Valid Accounts if the attacker has legitimate credentials but abuses their privileges during a restore operation. It also touches upon T1496 Resource Hijacking if the injected content causes denial of service through resource exhaustion, though the primary concern remains unauthorized information disclosure. The flaw highlights a critical gap in how legacy systems handle state transitions and data migration processes, where historical context is not properly isolated from current operational contexts.
Mitigation strategies must prioritize immediate patching to version 25.04.5 or later for the 25.x branch and version 26.04.1 or later for the 26.x branch, as these releases contain corrections that enforce stricter validation of section identifiers during backup restoration. Until patches are applied, administrators should restrict who has permission to export and import site backups, ensuring that only trusted individuals with a need-to-know basis can perform these operations. Additionally, implementing strict input validation on any custom scripts or plugins that interact with the Text block API is advisable. Security teams should also audit existing backup files for anomalies if there is suspicion of prior exploitation, although detection may be difficult without detailed logging enabled for restore actions. Regular security assessments focusing on data flow and access control logic during migration processes are recommended to prevent similar logical flaws in other modules of the platform.