Description
A flaw was found in Keycloak's Dynamic Client Registration (DCR) security policy management. The "Allowed Protocol Mapper Types" policy, which restricts which types of data mappers a client can use, fails to re-validate the mapper type during a client update if the mapper's configuration remains unchanged. An attacker with client registration privileges can exploit this by first registering an allowed mapper type with a malicious configuration and then swapping it for a restricted, high-privilege mapper type (such as one that hardcodes administrative roles). This allows the attacker to gain full administrative access to the Keycloak realm.
Affected products
redhat: build of keycloak
References6
- access.redhat.com/errata/RHSA-2026:50846 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:50847 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:50848 Vendor Advisory
- access.redhat.com/errata/RHSA-2026:50849 Vendor Advisory
- access.redhat.com/security/cve/CVE-2026-15572 Vendor Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2499592 Issue TrackingVendor Advisory
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 52 · as of 13 November 2026
- CWE
- CWE-843
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.