OpenFGA up to 1.18.0 ListUsers API list_users_rpc.go expandIntersection improper authorization

Summaryinfo

A vulnerability identified as problematic has been detected in OpenFGA up to 1.18.0. This impacts the function expandIntersection of the file pkg/server/commands/listusers/list_users_rpc.go of the component ListUsers API. The manipulation leads to improper authorization. This vulnerability is listed as CVE-2026-61709. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenFGA up to 1.18.0. It has been rated as problematic. This issue affects the function expandIntersection of the file pkg/server/commands/listusers/list_users_rpc.go of the component ListUsers API. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-61709 since 07/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

Upgrading to version 1.18.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-80777). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• OpenFGA

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18.0

Website

• Product: https://github.com/openfga/openfga/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion