SpiceDB is an open source, Google Zanzibar-inspired, database system for creating and managing security-critical application permissions. Any user making a negative authorization decision based on the results of a "LookupResources" request with 1.22.0 is affected. For example, using "LookupResources" to find a list of resources to allow access to be okay: some subjects that should have access to a resource may not. But if using "LookupResources" to find a list of banned resources instead, then some users that shouldn't have access may. Generally, "LookupResources" is not and should not be to gate access in this way - that's what the "Check" API is for. Additionally, version 1.22.0 has included a warning about this bug since its initial release. Users are advised to upgrade to version 1.22.2. Users unable to upgrade should avoid using "LookupResources" for negative authorization decisions.