What’s Vulnerable › Vulnerabilities

CVE-2026-61709: OpenFGA: ListUsers returns a deliberately-excluded user (authorization-decision over-inclusion) when a `but not` exclusion under a type-bound wildcard is intersected (`and`) with another relation that also grants that user

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-16 · updated 2026-09-24
• Weakness: CWE-281

Description

OpenFGA is an authorization and permission engine built for developers. Prior to 1.18.1, the ListUsers API could return a user that should have been excluded when an authorization relation used an intersection containing a base but not excluded operand, the base was granted through a type-bound public wildcard, and the excluded user also had a concrete tuple through another intersection operand. In pkg/server/commands/listusers/list_users_rpc.go, expandIntersection counted the concrete tuple and wildcard without first rejecting entries in excludedUsersMap. Applications that used ListUsers to enumerate or enforce access could therefore treat an excluded user as authorized. This issue is fixed in version 1.18.1.

Affected products

• openfga: before 1.18.1

References

• https://github.com/openfga/openfga/commit/171806c93b86bca29e0212ceb8b6ee9c48eb9ac3
• https://github.com/openfga/openfga/releases/tag/v1.18.1
• https://github.com/openfga/openfga/security/advisories/GHSA-g3pg-frfm-pr2m

Get alerted when CVE-2026-61709 or the next vulnerability affects your stack