Vulnerability · Published Aug 5, 2026 · Assigned by redhat
CVE-2026-16443Keycloak-services: keycloak-services: saml broker metadata import disables response signature validation
High 7.4
In plain English
A high-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 25% of all known vulnerabilities).
Official description
A flaw was found in the SAML metadata import functionality of the keycloak-services component, which is the core engine for identity brokering in Red Hat Build of Keycloak. When importing identity provider metadata that lacks specific usage attributes for keys, the system incorrectly disables signature validation for SAML responses even if a signing certificate is provided. This issue allows an unauthenticated attacker to forge a SAML response and gain unauthorized access to a user account by knowing their external identifier.
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 26.4.14 | see references |
| Red Hat | Red Hat build of Keycloak 26.4.14 | see references |
| Red Hat | Red Hat build of Keycloak 26.6 | see references |
| Red Hat | Red Hat build of Keycloak 26.6 | see references |
| Red Hat | Red Hat build of Keycloak 26.6 | see references |
| Red Hat | Red Hat build of Keycloak 26.6.5 | see references |
| Red Hat | Red Hat build of Keycloak 26.6.5 | see references |
| Red Hat | Red Hat build of Keycloak 26.6.5 | see references |
| Red Hat | Red Hat Data Grid 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-347 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
References
- RHSA-2026:50846 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50847 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50848 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:50849 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-16443 vdb-entry, x_refsource_REDHAT
- RHBZ#2503139 issue-tracking, x_refsource_REDHAT