CVE-2026-33729: openfga Improper Input Validation

Vulnerability summary

CVE-2026-33729 is a critical (CVSS 9.8) Improper Input Validation vulnerability in openfga. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22% of scored vulnerabilities.

Timeline

1. 27-03-2026
   PublishedVulnerability first disclosed.
2. 30-03-2026
   Last modifiedVulnerability information updated.

Description

OpenFGA is a high-performance and flexible authorization/permission engine built for developers and inspired by Google Zanzibar. In versions prior to 1.13.1, under specific conditions, models using conditions with caching enabled can result in two different check requests producing the same cache key. This can result in OpenFGA reusing an earlier cached result for a different request. Users are affected if the model has relations which rely on condition evaluation andncaching is enabled. OpenFGA v1.13.1 contains a patch.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-345Insufficient Verification of Data AuthenticityThe product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
• CWE-1289Improper Validation of Unsafe Equivalence in InputThe product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.