CVE-2026-86283 in MISP
Summary
by MITRE • 09/06/2026
MISP's UiBeta theme collection view (app/View/Themed/UiBeta/Collections/view.ctp) performed a secondary query of member events by UUID without applying the caller's access control list (ACL). The CollectionsController::view() action correctly resolved collection element UUIDs through Event::fetchSimpleEvents($user, ...), which enforces per-user event ACL. However, the view template independently re-queried the same UUIDs using only an Event.uuid IN (...) condition, omitting the createEventConditions() authorization filter. Because collection element UUIDs are stored without server-side authorization against the referenced event (CollectionElementsController::add() accepts whatever UUID the collection owner posts), an authenticated user with view access to a collection could retrieve full details of events they are not permitted to read. The exposed data included event identifiers, info, dates, timestamps, creator organization, all event tags, and galaxy clusters (the latter attached via a cluster-scoped rather than event-scoped ACL check). This constitutes an authorization bypass at the presentation layer, allowing horizontal privilege escalation across event boundaries within the MISP instance.
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Analysis
by VulDB Data Team • 09/06/2026
The vulnerability identified in the Misp project represents a critical access control failure located within the UiBeta theme's collection view functionality. Specifically, the file app/View/Themed/UiBeta/Collections/view.ctp executes a secondary database query to retrieve member events based on their universally unique identifiers without enforcing the caller's access control list permissions. While the backend controller action CollectionsController::view() correctly utilizes Event::fetchSimpleEvents with user-specific parameters that enforce per-user event authorization, the frontend template independently re-queries these same UUIDs using only a simple SQL condition matching Event.uuid against a provided list. This architectural inconsistency creates a significant security gap where the presentation layer bypasses the server-side authorization logic implemented in the controller and model layers. The root cause lies in the assumption that data retrieved via direct identifier lookup is safe, ignoring the necessity of applying createEventConditions() or equivalent ACL filters to ensure the requesting user has explicit permission to view each specific event referenced by UUID.
This flaw allows authenticated users with basic access rights to a collection object to perform horizontal privilege escalation and retrieve full details of events they are otherwise prohibited from accessing. Because CollectionElementsController::add() accepts any valid UUID posted by the collection owner without performing server-side authorization checks against the target event, collections can inadvertently or maliciously include references to restricted events. When an authorized user views such a collection through the vulnerable UiBeta theme interface, the system returns comprehensive data for these unauthorized events. The exposed information is extensive and sensitive, including event identifiers, descriptive info fields, creation dates, timestamps, creator organization details, all associated tags, and galaxy clusters. Notably, galaxy cluster data was also exposed due to a separate issue where cluster-scoped ACL checks were not properly applied during this retrieval process, further compounding the severity of the information disclosure.
From a classification perspective, this vulnerability aligns with CWE-285 Improper Authorization, as the application fails to enforce proper access controls when granting users access to resources belonging to other entities or contexts. It also maps directly to MITRE ATT&CK technique T1078 Valid Accounts, specifically within the context of lateral movement and privilege escalation via valid credentials that are misused due to flawed authorization logic. The attack vector is remote but requires authentication, meaning an attacker must first compromise a low-privilege account or exploit another vulnerability to gain initial access before leveraging this flaw to escalate privileges and exfiltrate sensitive threat intelligence data stored within the MISP instance.
Mitigation strategies should focus on enforcing consistent authorization checks across all layers of the application stack. The primary fix involves modifying the view template or its associated helper functions to ensure that any query retrieving event details by UUID also applies the necessary ACL filters, such as createEventConditions(), before returning data to the user. Alternatively, the backend controller should be refactored to handle all data retrieval logic for collection views, ensuring that no direct database queries are executed in the presentation layer without passing through authorized service methods. Additionally, input validation at the CollectionElementsController::add() level must be strengthened to verify that the event owner of any referenced UUID permits access by the user creating or modifying the collection element. Regular security audits and static code analysis tools configured to detect unauthorized direct object references should be employed to prevent similar architectural flaws in future development cycles.