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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.2 | — | — |
| Red Hat | Red Hat build of Keycloak 26.2.15 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4.11 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | keycloak-26.4-iamguarded-compat | No fix yet | — |
| Wolfi rolling | keycloak-26.5 +1 | 26.5.7-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-services | < 26.5.7 | 26.5.7 | GHSA-f2hx-5fx3-hmcv |
Advisories 1
- WID-SEC-2026-0977 Keycloak: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 13, 2026
References
- RHSA-2026:6475 vendor-advisory
- RHSA-2026:6476 vendor-advisory
- RHSA-2026:6477 vendor-advisory
- RHSA-2026:6478 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-4636 vdb-entry
- RHBZ#2450251 issue-tracking