SurrealDB before 3.3.0 does not check the caller-selected namespace or database against the level at which a namespace- or database-level system user authenticated, allowing cross-tenant access. An authenticated attacker can set the Surreal-NS/Surreal-DB headers on /sql or call the RPC use method to read, create, modify, and delete rows and read DEFINE PARAM values in another tenant where table PERMISSIONS allow it.