CVE-2023-35933
MediumCVSS 5.9Exploitation Probability (EPSS)
Elevated risk56th percentile - higher than 56% of all known CVEs
Summary
OpenFGA versions v1.1.0 and prior are vulnerable to a DoS attack when Check and ListObjects calls are executed against authorization models that contain circular relationship definitions. Users are affected if they are using these versions and executing these calls on vulnerable models.
Risk Assessment
A DoS attack can lead to unavailability of authorization services, impacting application functionality and potentially causing significant disruptions within the organization.
Recommendation
It is recommended to upgrade to version 1.1.1 of OpenFGA to mitigate this vulnerability. Users without circular relationships in their models are not affected.
Other vulnerabilities in OpenFGA
See all- CVE-2026-61709Medium
In OpenFGA prior to 1.18.1, the ListUsers API could return a user that should have been excluded when an authorization relation used an intersection containing a base but not excluded operand, the base was granted through a type-bound public wildcard, and the excluded user also had a concrete tuple through another intersection operand. Applications using ListUsers to enforce access could treat an excluded user as authorized.
- CVE-2026-55689Medium
In OpenFGA prior to version 1.18.0, the OIDC authenticator skipped JWT audience validation when authn.method was set to oidc, authn.oidc.issuer was configured, and authn.oidc.audience was not set. This allows a token minted for an unrelated service by the same identity provider to authenticate to OpenFGA.
- CVE-2026-55170Medium
In OpenFGA prior to version 1.18.0, when MySQL is used as the datastore, the tuple, changelog, and authorization_model identifier columns compare case-distinct values (e.g., user:Alice and user:alice) as equivalent, causing two distinct check requests to return the same response.
- CVE-2026-48096Medium
OpenFGA, an authorization engine, prior to version 1.16.0, had an issue with iterator caching where two distinct check requests could produce the same cache key. This led to the reuse of an earlier cached result for a subsequent request.
- CVE-2026-40293Medium
In OpenFGA versions 0.1.4 through 1.13.1, when configured with preshared-key authentication and the built-in playground enabled, the local server includes the preshared API key in the HTML response of the /playground endpoint. This endpoint is enabled by default and does not require authentication, potentially leading to sensitive data exposure.
- CVE-2026-34972Medium
OpenFGA, a high-performance authorization/permission engine, has a vulnerability in BatchCheck calls where multiple checks for the same object, relation, and user combination can result in improper policy enforcement. This affects versions 1.8.0 to 1.13.1.
Original NVD description (English source)
OPenFGA is an open source authorization/permission engine built for developers. OpenFGA versions v1.1.0 and prior are vulnerable to a DoS attack when Check and ListObjects calls are executed against authorization models that contain circular relationship definitions. Users are affected by this vulnerability if they are using OpenFGA v1.1.0 or earlier, and if you are executing `Check` or `ListObjects` calls against a vulnerable authorization model. Users are advised to upgrade to version 1.1.1. There are no known workarounds for this vulnerability. Users that do not have circular relationships in their models are not affected.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

