CVE-2026-16442 Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction
Attackers can bypass link-only restrictions in SAML broker logins to gain full access to local user accounts in Keycloak.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-16442?
CVE-2026-16442 is a high-severity authentication bypass vulnerability in Redhat Build of Keycloak, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in the SAML broker component of Keycloak, which is used to manage identity federation and user authentication. The issue occurs because the IdP-initiated Single Sign-On endpoint fails to check if a provider is restricted to account linking only. This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account.
Weakness: CWE-346
Which versions are affected by CVE-2026-16442?
1 open source package ship an affected version, including keycloak. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
keycloak Bitnami | From 26.4.0 | 26.4.14, 26.6.5 |
Products include Redhat Build of Keycloak.
How do I fix CVE-2026-16442?
Upgrade keycloak to a fixed version for your release line: 26.4.14 or 26.6.5.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-16442 being exploited?
There is no known exploitation of CVE-2026-16442 in the wild and no public exploit code.
Other vulnerabilities in Redhat Build of Keycloak
- CVE-2026-15572 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation
- CVE-2026-3047 Keycloak SAML Broken has Authentication Bypass by Primary Weakness
- CVE-2026-15573 Keycloak-services: keycloak-services: authorization bypass via unnormalized uri matching in pathmatcher
- CVE-2026-16102 Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers
- CVE-2026-1609 Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
Sources
Also known as BIT-keycloak-2026-16442, GHSA-vj6m-hv26-qx79.