OpenFGA Vulnerable to DoS from circular relationship definitions

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2023-43645: 0.94% estimated exploitation activity in the next 30 days; percentile 60.89 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Overview OpenFGA is vulnerable to a DoS attack when certain Check calls are executed against authorization models that contain circular relationship definitions. When the call is made, it's possible for the server to exhaust resources and die. Am I Affected? Yes, if your store contains an authorization model that allows circular relationships. For example, with this model: This Check: (user:anne, memberA, group:X) can exhaust memory in the server. Fix Upgrade to v1.3.2 and update any offending models. [BREAKING] If your model contained cycles or a relation definition that has the relation itself in its evaluation path, then Checks and queries that require evaluation will no longer be evaluated on v1.3.2+ and will return errors instead. You will need to update your models to remove the cycles.

Published by the source

28 Sep 2023, 21:27 UTC

Last modified by the source

10 Nov 2023, 05:05 UTC

Source last checked

26 Oct 2026, 15:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2hm9-h873-pgqh

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# Patch Next advisory brief: CVE-2023-43645

Advisory: OpenFGA Vulnerable to DoS from circular relationship definitions
IDs: CVE-2023-43645, GHSA-2hm9-h873-pgqh
Record: https://patchnext.com/advisories/cve-2023-43645 (revision 1, source checked 26 Oct 2026, 15:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/openfga/openfga 1.3.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/openfga/openfga: affected < 1.3.2; fixed in 1.3.2

## Suggested inspection (read-only)
- Go github.com/openfga/openfga: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/openfga/openfga.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2hm9-h873-pgqh (GitHub-reviewed advisory GHSA-2hm9-h873-pgqh lists affected ranges: Go github.com/openfga/openfga >=0 <1.3.2)

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