How severe is GHSA-mgh9-4mwp-fg55?

No CVSS score has been assigned to GHSA-mgh9-4mwp-fg55 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-mgh9-4mwp-fg55?

GHSA-mgh9-4mwp-fg55 affects the following packages: github.com/openfga/openfga (Go). Ecosystems affected: Go.

How do I fix GHSA-mgh9-4mwp-fg55?

Update github.com/openfga/openfga to 1.9.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mgh9-4mwp-fg55 is resolved across your whole dependency graph.

How do I detect GHSA-mgh9-4mwp-fg55 in my Go dependencies?

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.

How do I mitigate GHSA-mgh9-4mwp-fg55 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is GHSA-mgh9-4mwp-fg55 actively exploited in the wild?

No public exploit code has been indexed for GHSA-mgh9-4mwp-fg55 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-mgh9-4mwp-fg55?

GHSA-mgh9-4mwp-fg55 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 28th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-mgh9-4mwp-fg55?

GHSA-mgh9-4mwp-fg55 is classified as CWE-863 (CWE-863). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-mgh9-4mwp-fg55 published, and has it been updated?

GHSA-mgh9-4mwp-fg55 was published on August 18, 2025 and was last updated on August 29, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

OpenFGA Authorization BypassGHSA-mgh9-4mwp-fg55

Fix: openfga/openfga@1a7e0e3

GHSA-mgh9-4mwp-fg55 is a CWE-863 vulnerability in github.com/openfga/openfga. A fix is available for github.com/openfga/openfga — see the affected versions and patch details below.

Also known asCVE-2025-55213GO-2025-3894

Published

Aug 18, 2025

Updated

Aug 29, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-mgh9-4mwp-fg55.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk+0.02%

Lower risk than most CVEs28th percentile — riskier than 28% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐹github.com/openfga/openfga

Real-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 v1.9.3 to v1.9.4 ( openfga-0.2.40 <= Helm chart <= openfga-0.2.41, v1.9.3 <= docker <= v.1.9.4) are vulnerable to improper policy enforcement when certain Check and ListObject calls are executed.

Am I Affected?

You are affected by this vulnerability if you are using OpenFGA v1.9.3 to v1.9.4, specifically under the following preconditions:

Calling Check API or ListObjects with an authorization model that has a relationship directly assignable by more than 1 userset with same type, and
There are check or list object queries that rely on the above relationship, and
You have userset tuples that are assigned to the above relationship

Fix

Upgrade to v1.9.5. This upgrade is backwards compatible.

Workaround

Downgrade to v1.9.2 with enable-check-optimizations removed from OPENFGA_EXPERIMENTALS

Acknowledgments

OpenFGA would like Dominic Harries and rrozza-apolitical to thank for discovering this vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/openfga/openfga`	≥ 1.9.3&&< 1.9.5	1.9.5`go get github.com/openfga/openfga@v1.9.5`

Affected Products

2 products · 2 configurations

Application

helm chartsopenfga

≥ 0.2.40 && < 0.2.42

range

Application

openfgaopenfga

≥ 1.9.3 && < 1.9.5

range

Detection & mitigation playbook

Open-source dependency

Detect
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 1.9.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mgh9-4mwp-fg55 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for GHSA-mgh9-4mwp-fg55 (CC BY 4.0)

Frequently Asked Questions

### Overview OpenFGA v1.9.3 to v1.9.4 ( openfga-0.2.40 <= Helm chart <= openfga-0.2.41, v1.9.3 <= docker <= v.1.9.4) are vulnerable to improper policy enforcement when certain Check and ListObject calls are executed. ### Am I Affected? You are affected by this vulnerability if you are using OpenFGA v1.9.3 to v1.9.4, specifically under the following preconditions: - Calling Check API or ListObjects with an [authorization model](https://openfga.dev/docs/concepts#what-is-an-authorization-model) that has a relationship directly assignable by more than 1 [userset](https://openfga.dev/docs/modeling

O3 Security · Impact-Aware SCA

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