OpenFGA has an Authorization Bypass through cached keys

OpenFGA's caching system can incorrectly reuse cached authorization results for different requests when conditions are involved, allowing an attacker to bypass access controls by triggering the same cache key for a different user or permission check.

In OpenFGA versions before 1.13.1, models using condition evaluation with caching enabled generate identical cache keys for distinct authorization requests, leading to authorization bypass. The vulnerability requires conditions to be present in relations and caching to be active; an attacker exploits this by crafting requests that collide with cached results from prior checks with different authorization contexts.