GHSA-hr9r-8phq-5x8j is a medium-severity (CVSS 5.9) CWE-835 vulnerability in github.com/openfga/openfga. 2 public exploit references exist, so weaponization risk is real. A fix is available for github.com/openfga/openfga — see the affected versions and patch details below.
OpenFGA vulnerable to denial of service due to circular relationship
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hr9r-8phq-5x8j.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-hr9r-8phq-5x8j plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/openfga/openfgaReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Overview
OpenFGA versions v1.1.0 and prior are vulnerable to a DoS attack when certain Check and ListObjects calls are executed against authorization models that contain circular relationship definitions.
Am I Affected?
You are affected by this vulnerability if you are using OpenFGA v1.1.0 or earlier, and if you are executing certain Check or ListObjects calls against a vulnerable authorization model. To see which of your models could be vulnerable to this attack, download OpenFGA v1.2.0 and run the following command:
./openfga validate-models --datastore-engine <ENGINE> --datastore-uri <URI> | jq .[] | select(.Error | contains("loop"))
replacing the variables <ENGINE> and <URI> as needed.
Fix
Upgrade to v1.1.1.
Backward Compatibility
If you are not passing an invalid authorization model (as identified by running ./openfga validate-models) as a parameter of your Check and ListObjects calls, this upgrade is backwards compatible.
Otherwise, OpenFGA v1.1.1 will start returning HTTP 400 status codes on those calls.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/openfga/openfga | all versions | 1.1.1go get github.com/openfga/openfga@v1.1.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/openfga/openfga, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/openfga/openfga to 1.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hr9r-8phq-5x8j is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-hr9r-8phq-5x8j can be triaged on real exposure rather than presence alone.
Tailored to GHSA-hr9r-8phq-5x8j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-hr9r-8phq-5x8j in your dependencies?
O3 Security finds GHSA-hr9r-8phq-5x8j across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.