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
### Description In OpenFGA, the ListUsers API could incorrectly return a user who should have been excluded. ### Preconditions This applies if all of the following are present: - The authorization model contains a relation defined as an intersection (and) where at least one operand is an exclusion of the form base but not excluded: e.g. `rel1: (public_user but not blocked) and rel2` - The base side of that exclusion is granted through a type-bound public wildcard (e.g. user:*). - A user excluded by the but not clause is also granted, via a concrete tuple, through another operand of the intersection. - Your application uses ListUsers to enumerate or enforce access ### Fix Upgrade to OpenFGA v1.18.1 or greater. ### Acknowledgements OpenFGA would like to thank @5ud0er for the detailed report.
GHSA-g3pg-frfm-pr2m
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-g3pg-frfm-pr2m
github.com/openfga/openfga
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.18.1
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.18.1"
}
]
}
],
"package": {
"name": "github.com/openfga/openfga",
"purl": "pkg:golang/github.com/openfga/openfga",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-g3pg-frfm-pr2m/GHSA-g3pg-frfm-pr2m.json",
"last_known_affected_version_range": "<= 1.18.0"
}
}
]- Related CVEs
- CVE-2026-61709
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #23416 · Revision 1
- Added to Heist Feed
- Publisher date