Critical (9.8) in openfga openfga. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in github.com/openfga/openfga 1.5.9.
OpenFGA is an authorization/permission engine. OpenFGA v1.5.7 and v1.5.8 are vulnerable to authorization bypass when calling Check API with a model that uses `but not` and `from` expressions and a userset. Users should downgrade to v1.5.6 as soon as possible. This downgrade is backward compatible. As of time of publication, a patch is not available but OpenFGA's maintainers are planning a patch for inclusion in a future release.
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-31)