CVE-2026-86451: MISP Event Graph Object Reference Lookup Exposes References from Unauthorized Objects
Affected versions of MISP allow authenticated users to retrieve object-reference records by UUID through EventGraphTool::getreferencedata() without first checking whether the requester is authorized to view the object the reference belongs to.
The vulnerable code queried ObjectReference.uuid directly and returned the matching row whenever it existed. Because no parent-object ACL was applied, a user who knew or obtained a reference UUID could retrieve information associated with an object outside their normal access scope. The commit explicitly states that any object reference could be returned by UUID without authorizing its parent object.
The fix retrieves the referenced object's objectid and calls fetchObjectSimple() with the current user. If the user cannot access that parent object, MISP now returns NotFoundException instead of exposing the reference.
Version affected: ≤2.5.45
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MISPto a version that resolves this vulnerability.Fixed in 2.5.45
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker must be authenticated to MISP and know or obtain the UUID of an object-reference record. The issue can expose reference information associated with a parent object that the authenticated user is not authorized to view.
Which versions need remediation?
MISP versions 2.5.45 and earlier are affected. The referenced fix adds a parent-object authorization check before returning reference data.
How does the fixed behavior differ when access is denied?
The fix resolves the reference's parent object and checks access using the current user. If that user cannot access the parent object, MISP returns a NotFoundException rather than returning the reference record.