Keycloak: keycloak: uma policy bypass allows authenticated users to gain unauthorized access to victim-owned resources. (Red Hat Red Hat build of Keycloak 26.2)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.44 % · percentile 38 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Modified
Description
A flaw was found in Keycloak. An authenticated user with the uma_protection role can bypass User-Managed Access (UMA) policy validation. This allows the attacker to include resource identifiers owned by other users in a policy creation request, even if the URL path specifies an attacker-owned resource. Consequently, the attacker gains unauthorized permissions to victim-owned resources, enabling them to obtain a Requesting Party Token (RPT) and access sensitive information or perform unauthorized actions.
Weaknesses (CWE)
- CWE-551 — Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
References
- https://access.redhat.com/errata/RHSA-2026:6475
- https://access.redhat.com/errata/RHSA-2026:6476
- https://access.redhat.com/errata/RHSA-2026:6477
- https://access.redhat.com/errata/RHSA-2026:6478
- https://access.redhat.com/security/cve/CVE-2026-4636
- https://bugzilla.redhat.com/show_bug.cgi?id=2450251
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4636.json
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | redhat |
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | redhat-SADP |
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | NVD · secalert@redhat.com (Secondary) |
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Advisories
- GHSA-f2hx-5fx3-hmcv — Keycloak: UMA Policy Resource Injection Allows Unauthorized Cross-User Permission Grants
European references
- ENISA EUVD · EUVD-2026-18213
- GCVE · GCVE-0-2026-4636
Affected configurations (NVD CPE)
cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:text-only:*:*:*cpe:2.3:a:redhat:build_of_keycloak:26.2:*:*:*:text-only:*:*:*cpe:2.3:a:redhat:build_of_keycloak:26.2.15:*:*:*:text-only:*:*:*cpe:2.3:a:redhat:build_of_keycloak:26.4:*:*:*:text-only:*:*:*cpe:2.3:a:redhat:build_of_keycloak:26.4.11:*:*:*:text-only:*:*:*
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat build of Keycloak 26.2 | unaffected 26.2.15-1 < * |
| Red Hat · Red Hat build of Keycloak 26.2 | unaffected 26.2-18 < * |
| Red Hat · Red Hat build of Keycloak 26.2 | unaffected 26.2-18 < * |
| Red Hat · Red Hat build of Keycloak 26.2.15 | |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4.11-1 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-14 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-14 < * |
| Red Hat · Red Hat build of Keycloak 26.4.11 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |