Vulnerability · Published Feb 27, 2026 · Assigned by redhat
CVE-2026-0871Org.keycloak/keycloak-services: keycloak: unauthorized modification of unmanaged user attributes by administrators
Medium 4.9
In plain English
A medium-severity security flaw in Red Hat build of Keycloak 26.4 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A flaw was found in Keycloak. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to unauthorized changes to user profiles, even when the system is configured to restrict such modifications.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.keycloak:keycloak-server-spi-private | 26.5.2 | GHSA-v4jw-m6rm-399h |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4 | see references |
| Red Hat | Red Hat build of Keycloak 26.4.9 | see references |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | see references |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | see references |
| Red Hat | Red Hat Single Sign-On 7 | see references |
Weakness: CWE-266 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
References
- RHSA-2026:2365 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:2366 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-0871 vdb-entry, x_refsource_REDHAT
- RHBZ#2428881 issue-tracking, x_refsource_REDHAT