CVE-2026-16102
The default DCR policy fails to properly validate the claim path for User Property mappers, allowing them to write values to sensitive internal claim locations.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A flaw was found in the Dynamic Client Registration (DCR) component of Keycloak, an identity and access management solution. The default DCR policy fails to properly validate the claim path for User Property mappers, allowing them to write values to sensitive internal claim locations. An attacker with a standard user account and a limited Initial Access Token can exploit this to forge administrative roles in their access token. This allows the attacker to take over other clients, steal confidential secrets, and potentially gain full administrative control over the realm.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 0.32% probability · 25th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-551, CWE-284
- Affected
- redhat/build of keycloak · redhat/data grid · redhat/jboss enterprise application platform expansion pack · redhat/single sign-on
- Source
- secalert@redhat.com
References
- https://access.redhat.com/errata/RHSA-2026:50846Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:50847Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:50848Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:50849Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-16102Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2501735Issue Tracking
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.