NIXPKGS-2026-2623

GitHub issue published 13 hours ago

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

Permalink CVE-2026-61709

5.3 MEDIUM

CVSS version (CVSS): 3.1
Attack Vector (AV): Network (N)
Attack Complexity (AC): High (H)
Privileges Required (PR): Low (L)
User Interaction (UI): None (N)
Scope (S): Unchanged (U)
Confidentiality (C): High (H)
Integrity (I): None (N)
Availability (A): None (N)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): High (H)
Modified Privileges Required (MPR): Low (L)
Modified User Interaction (MUI): None (N)
Modified Confidentiality (MC): High (H)
Modified Scope (MS): Unchanged (U)
Modified Integrity (MI): None (N)
Modified Availability (MA): None (N)

updated 13 hours ago by @LeSuisse Activity log

Created suggestion 1 day ago
@LeSuisse ignored
3 packages
- python313Packages.openfga-sdk
- openfga-cli
- python314Packages.openfga-sdk
17 hours ago
@LeSuisse accepted 17 hours ago
@LeSuisse published on GitHub 13 hours ago

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.