CVE-2026-4282: Keycloak: keycloak: privilege escalation via forged authorization codes due to singleuseobjectprovider isolation flaw

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-02 · updated 2026-10-26
Weakness: CWE-653

Description

A flaw was found in Keycloak. The SingleUseObjectProvider, a global key-value store, lacks proper type and namespace isolation. This vulnerability allows an unauthenticated attacker to forge authorization codes. Successful exploitation can lead to the creation of admin-capable access tokens, resulting in privilege escalation.

Affected products

Red Hat build of Keycloak 26.4: 26.2, 26.2.15, 26.4, 26.4.11

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-2026-4282
https://bugzilla.redhat.com/show_bug.cgi?id=2448061
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-2026-4282
https://bugzilla.redhat.com/show_bug.cgi?id=2448061

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