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PatchSiren cyber security CVE debrief

CVE-2026-9795 Red Hat CVE debrief

A privilege escalation vulnerability exists in Keycloak's Fine-Grained Admin Permissions (FGAPv2) feature. An administrator with limited client management permissions can assign arbitrary realm roles—including highly privileged roles—to a client's scope mapping. This bypasses intended access controls and causes the injected role to be projected into user authentication tokens when accessing the modified client, enabling unauthorized privilege escalation within the Keycloak realm.

Vendor
Red Hat
Product
Red Hat Build of Keycloak
CVSS
HIGH 7.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-28
Original CVE updated
2026-05-28
Advisory published
2026-05-28
Advisory updated
2026-05-28

Who should care

Organizations operating Keycloak identity and access management infrastructure with FGAPv2 enabled; security teams managing delegated administrative permissions; compliance officers responsible for least-privilege enforcement in identity systems

Technical summary

The vulnerability resides in Keycloak's Fine-Grained Admin Permissions version 2 (FGAPv2), which provides granular administrative access control. The flaw allows an administrator possessing only limited client management permissions to circumvent intended restrictions and assign any realm role to a client's scope mapping configuration. When users subsequently authenticate to the modified client, the injected role is projected into their access tokens. This represents an incorrect privilege assignment (CWE-266) where the scope mapping modification capability is not properly constrained by the administrator's own role limitations. The attack requires network access (AV:N), high attack complexity (AC:H), high privileges (PR:H), and user interaction (UI:R), with changed scope (S:C) enabling impact on confidentiality (C:H) and integrity (I:H) of the affected system.

Defensive priority

HIGH

Recommended defensive actions

  • Review and restrict client management permissions for administrators using FGAPv2
  • Audit client scope mappings for unauthorized role assignments
  • Monitor authentication tokens for unexpected role projections
  • Apply vendor patches when available from Red Hat
  • Review Keycloak admin audit logs for suspicious scope mapping modifications

Evidence notes

CVE published 2026-05-28T05:16:41.003Z; modified 2026-05-28T13:44:54.327Z. Vendor attribution to Red Hat based on source references. CVSS 7.3 (HIGH). CWE-266 (Incorrect Privilege Assignment).

Official resources

2026-05-28