CVE-2026-111667 in Rebuild
Summary
by MITRE • 10/16/2026
REBUILD through 4.5.0 contains a missing authorization vulnerability in TaskCommentController.commentList that allows authenticated low-privileged users to read task comments without project membership checks. Attackers can supply the id of a task in a private project to the /project/comments/list endpoint to retrieve its comment content and attachment references.
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Analysis
by VulDB Data Team • 10/16/2026
The identified vulnerability represents a critical breakdown in access control mechanisms within the REBUILD software, specifically affecting versions up through 4.5.0. This flaw is located in the TaskCommentController.commentList functionality, which serves as an endpoint for retrieving comments associated with specific tasks. The core issue stems from insufficient authorization checks during the request processing phase. While the system correctly verifies that a user is authenticated to access the application, it fails to validate whether the authenticated user possesses the necessary permissions or project membership rights relative to the target task. This oversight allows any logged-in user, regardless of their privilege level or association with the specific project, to query and retrieve sensitive data by simply providing the identifier of a task housed within a private project.
From a technical perspective, this vulnerability is classified as an Insecure Direct Object Reference (IDOR), which aligns with CWE-639 in the Common Weakness Enumeration standards. The attacker exploits this weakness by manipulating the input parameters sent to the /project/comments/list endpoint. By supplying arbitrary task IDs that belong to private projects where they are not members, the application erroneously returns the requested comment content and associated attachment references. This behavior indicates a failure to implement proper object-level access control checks before processing the request or returning data. The absence of these checks means that the security boundary defined by project membership is effectively bypassed through direct manipulation of resource identifiers.
The operational impact of this vulnerability is significant, particularly regarding confidentiality and intellectual property protection. Private projects are typically intended for restricted collaboration among specific team members, containing sensitive business information, strategic plans, or proprietary code discussions within their comment threads. The ability to read these comments without authorization exposes confidential communications to unauthorized parties. Furthermore, the retrieval of attachment references can lead to further data leakage if those attachments contain sensitive documents, designs, or credentials. This exposure undermines trust in the platform's security model and could result in regulatory non-compliance for organizations handling protected data under frameworks such as GDPR or HIPAA, depending on the nature of the information disclosed.
To mitigate this vulnerability, immediate action is required to patch the affected versions up through 4.5.0 by applying the vendor-provided update that addresses these access control flaws. In addition to upgrading, developers should implement rigorous authorization checks at both the controller and service layers. Specifically, every request to retrieve task-related data must verify that the requesting user has explicit read permissions for the specific project containing the target task. This involves cross-referencing the user's role and membership status against a secure access control list before executing database queries or returning API responses. Adhering to the principle of least privilege ensures that users only interact with resources they are explicitly authorized to access, thereby preventing unauthorized data exfiltration via IDOR attacks.