Description
A flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.2 | — | — |
| Red Hat | Red Hat build of Keycloak 26.2.14 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4.10 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | keycloak-26.4-iamguarded-compat | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-server-spi-private | < 26.5.5 | 26.5.5 | GHSA-x4p7-7chp-64hq |
| Maven | org.keycloak:keycloak-services | < 26.5.5 | 26.5.5 | GHSA-x4p7-7chp-64hq |
Advisories 1
- WID-SEC-2026-0622 Keycloak: Mehrere Schwachstellen ermöglichen Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Mar 17, 2026
References
- RHSA-2026:3925 vendor-advisory
- RHSA-2026:3926 vendor-advisory
- RHSA-2026:3947 vendor-advisory
- RHSA-2026:3948 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-2603 vdb-entry
- RHBZ#2440300 issue-tracking