CVE-2026-71854 in OpenAEV
Summary
by MITRE • 10/15/2026
OpenAEV is an open source platform allowing organizations to plan, schedule and conduct cyber adversary simulation campaign and tests. Prior to version 2.260622.0, on a default installation, the `/api/player/**` lessons endpoints can be called without authentication, and they trust a client-supplied `userId` query parameter without verifying that the caller is that user or a member of the exercise. An unauthenticated client that knows an exercise UUID can read lessons-learned questions and answers (including each answer's author identity) and create or overwrite answers attributed to an arbitrary user. Version 2.260622.0 contains a patch.
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Analysis
by VulDB Data Team • 10/15/2026
OpenAEV serves as an open-source platform designed for organizations to plan, schedule, and execute cyber adversary simulation campaigns and security tests. The software facilitates the management of red team exercises, allowing administrators and participants to engage in structured cybersecurity training scenarios. However, prior to version 2.260622.0, a critical authentication bypass vulnerability existed within the application's API layer, specifically affecting the endpoints associated with lesson execution under the path /api/player/**. This flaw stems from an insecure direct object reference mechanism where the system fails to enforce proper access controls on these specific routes during default installations.
The technical root cause of this vulnerability lies in how the server handles user identity verification for incoming requests. The application trusts a client-supplied userId query parameter without performing any validation to ensure that the caller is actually the owner of that account or a legitimate member of the ongoing exercise session. This lack of authorization checks allows an unauthenticated attacker who possesses knowledge of a valid exercise UUID to interact with sensitive endpoints as if they were authorized users. The system does not verify session tokens, API keys, or any other form of authentication before processing these requests, effectively rendering the access control mechanisms obsolete for this specific subset of functionality.
The operational impact of this vulnerability is severe due to the nature of data handled by OpenAEV. An unauthenticated actor can read lessons-learned questions and answers, which often contain sensitive insights into an organization's security posture, identified vulnerabilities, and remediation strategies. Furthermore, because the system attributes responses based on the supplied userId parameter rather than verified identity, attackers can create or overwrite answers while attributing them to arbitrary users within the exercise. This capability not only compromises data confidentiality but also undermines data integrity by allowing malicious actors to inject false information into the lessons-learned database, potentially misleading future security assessments and training outcomes.
This vulnerability aligns with CWE-284, which describes Improper Access Control, specifically highlighting the failure to verify user identity before granting access to resources. It is also closely related to CWE-639, Authorization Bypass Through User-Controlled Key, as the attacker leverages a controlled input parameter to bypass authorization checks. In terms of offensive security frameworks, this behavior corresponds to MITRE ATT&CK technique T1078, Valid Accounts, where an adversary uses legitimate credentials or identities to access resources they should not have permission to view or modify, although in this case, the identity is fabricated rather than stolen from a real account.
To mitigate this risk, organizations using OpenAEV must upgrade immediately to version 2.260622.0 or later, which contains the necessary patches to enforce proper authentication and authorization checks on all API endpoints. For environments where upgrading is not immediately feasible, network-level controls such as firewalls should be configured to restrict access to the /api/player/** paths exclusively from trusted internal networks if possible. Additionally, implementing strict input validation that rejects requests lacking valid session tokens or verifying that the userId parameter matches an authenticated user's identity would prevent exploitation of this flaw until a permanent software update is applied.