CVE-2026-81817 in Flowintel
Summary
by MITRE • 08/27/2026
Affected versions of Flowintel contain an insecure direct object reference / broken object-level authorization issue across numerous task endpoints.
The routes generally received both a case identifier and a task identifier, but previously they did not enforce that the task actually belonged to the supplied case. As a result, an authenticated user with editor-level access to one case could potentially substitute the ID of a task from another case and invoke operations against that foreign task.
The patch introduces task_case_bound_required, which loads both objects and returns 404 unless the task belongs to the requested case. This protection is applied to edit, delete, note, assignment, status, file, export, MISP-linking, subtask, external-reference, and other task-related endpoints.
The fix also adds explicit checks that a requested note_id belongs to the current task before returning or exporting it, closing related cross-object access paths.
Version impacted =>3.3.0
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Analysis
by VulDB Data Team • 08/27/2026
Versions of Flowintel prior to 3.3.0 are susceptible to insecure direct object references and broken object-level authorization vulnerabilities across multiple task-related endpoints. These routes typically accept both a case identifier and a task identifier as input parameters, but the application logic previously failed to enforce that the specified task actually belongs to the provided case context. This architectural flaw allows an authenticated user with editor-level access privileges on one specific case to manipulate request parameters by substituting the task ID of a foreign task associated with a different case. By doing so, the attacker can invoke operations against tasks they do not own or have permission to modify, effectively bypassing intended authorization controls and gaining unauthorized access to sensitive data within other cases.
The operational impact of this vulnerability is significant for organizations relying on Flowintel for secure case management and threat intelligence sharing. An adversary exploiting this flaw could read confidential information from unrelated cases by exporting task details, notes, or linked files. Furthermore, the ability to modify tasks enables potential tampering with investigation records, such as altering status updates, adding malicious notes, reassigning tasks to other users, or linking external references like MISP events incorrectly. This compromises the integrity of investigative workflows and may lead to data leakage if sensitive case details are exported by unauthorized parties. The vulnerability affects a wide range of endpoints including edit, delete, note management, assignment changes, status updates, file handling, export functions, MISP-linking, subtask creation, and external reference management, creating numerous attack vectors for exploitation.
The remediation strategy implemented in version 3.3.0 addresses these issues by introducing a new authorization middleware or logic component named task_case_bound_required. This mechanism explicitly loads both the case object and the task object from the database and verifies that the task is indeed associated with the requested case before proceeding with any operation. If this association check fails, the system returns an HTTP 404 Not Found response rather than a 403 Forbidden or allowing the action to proceed, which helps prevent information leakage through error messages while effectively blocking unauthorized access. This protection has been applied comprehensively across all identified vulnerable endpoints including edit, delete, note creation and retrieval, assignment modifications, status changes, file uploads and exports, MISP linking operations, subtask management, and external reference handling. Additionally, the patch introduces explicit validation checks to ensure that any requested note ID belongs to the current task before it is returned or exported, thereby closing related cross-object access paths where notes might otherwise be accessed independently of their parent task context.
From a classification perspective, this vulnerability aligns with CWE-639 Authorization Bypass Through User-Controlled Key and CWE-284 Improper Access Control, as the application failed to properly verify that the user had permission to act on the specific resource identified by the input keys. In terms of adversarial tactics, this flaw facilitates access to sensitive data through improper object-level authorization checks, which can be leveraged in conjunction with other techniques for lateral movement or data exfiltration within a compromised environment. Security practitioners should ensure that all API endpoints follow strict ownership verification patterns where resources are always validated against the context of the authenticated user and their associated entities. Implementing robust middleware that enforces these relationships at the framework level, rather than relying on scattered checks in individual route handlers, provides a more resilient defense against such authorization bypasses. Organizations running affected versions must upgrade to version 3.3.0 or later immediately to mitigate these risks and restore proper access control boundaries between distinct cases within the platform.