# OpenFGA: ListUsers returns a deliberately-excluded user when a \`but not\` exclusion under a type-bound wildcard is intersected (\`and\`) with another relation that also grants that user Advisory record · `GHSA-g3pg-frfm-pr2m` - **Identifiers:** `GHSA-g3pg-frfm-pr2m` · `CVE-2026-61709` · `GO-2026-6488` - **State:** Confirmed - **Severity:** CVSS 5.3 Medium - **Critical:** No - **Weakness (CWE):** [CWE-281](https://cwe.mitre.org/data/definitions/281.html) · [CWE-863](https://cwe.mitre.org/data/definitions/863.html) - **Tags:** [Broken access control](https://agentprime.io/advisories/tag/access-control.md) · [CWE-281](https://agentprime.io/advisories/tag/cwe-281.md) - **Published:** 16 Sept 2026 - **Updated:** 28 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 16 Sept 2026, 22:15 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `github.com/openfga/openfga` (Go): affected `<1.18.1`; fixed in `1.18.1` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > OpenFGA versions below 1.18.1 can have the ListUsers API return a user who should have been excluded. This affects models where an intersection includes an exclusion whose base side is granted through a type-bound public wildcard, and the excluded user also holds a concrete grant through another operand of the intersection. The source does not say what an attacker must control to trigger it. Upgrade to OpenFGA 1.18.1 or later. Written 1 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 5.3 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0035, the 28th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:12 UTC: First seen by agentprime - 31 Oct 2026, 14:12 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-g3pg-frfm-pr2m) ## Sources - [GitHub Advisory Database: GHSA-g3pg-frfm-pr2m](https://github.com/advisories/GHSA-g3pg-frfm-pr2m) - [OSV: GHSA-g3pg-frfm-pr2m](https://osv.dev/vulnerability/GHSA-g3pg-frfm-pr2m) - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .