CVE-2026-56422: MISP Core: Mass Assignment and Object Re-ownership via Unvalidated Request Fields

Multiple MISP core controllers and model capture paths accepted client-controlled request fields such as primary keys (id) and ownership/scope foreign keys (eventid, orgid, userid, sharinggroupid, galaxyclusteruuid, organisationuuid, and related nested object identifiers) without consistently stripping, pinning, or revalidating them against the server-authorized object.

In affected paths, an authenticated user with access to one authorized object could submit crafted REST or form payloads that caused MISP to save data against a different object than the one checked by the authorization logic. Depending on the endpoint, this could allow object overwrite, object re-parenting, ownership transfer, unauthorized sharing-group scoping, event/object injection, proposal retargeting, or stored attacker-controlled content appearing in another user’s context.

The fixes harden affected create/edit/import flows by stripping client-supplied primary keys on create-only saves, re-pinning route- or database-authorized identifiers before save operations, validating effective sharing-group scope, and adding field whitelists where ownership fields must never be editable. The initial broad fix also added a central CRUDComponent::edit() primary-key re-pin so payload-supplied IDs cannot redirect saves away from the already-authorized row. GitHub’s patch for 7acf8220c describes this central issue as CRUDComponent::edit() copying supplied fields, including a payload primary key, onto the loaded record, allowing CakePHP save() to update an arbitrary row unless the loaded ID is re-pinned.