Description
A flaw was found in Keycloak's SAML brokering functionality. When Keycloak is configured as a client in a Security Assertion Markup Language (SAML) setup, it fails to validate the `NotOnOrAfter` timestamp within the `SubjectConfirmationData`. This allows an attacker to delay the expiration of SAML responses, potentially extending the time a response is considered valid and leading to unexpected session durations or resource consumption.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat build of Keycloak 26.4 | — | — |
| Red Hat | Red Hat build of Keycloak 26.4.10 | — | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — |
| Red Hat | Red Hat Single Sign-On 7 | — | — |
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 | — |
| Wolfi rolling | keycloak-26.5 +1 | 26.5.3-r0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-services | <= 26.5.2 | — | GHSA-63v5-26vq-m4vm |
Advisories 1
- WID-SEC-2026-0147 Keycloak (SAML brokering): Schwachstelle ermöglicht Manipulation von Dateien BSI CERT-Bund (WID) · Apr 6, 2026
References
- RHSA-2026:3947 vendor-advisory
- RHSA-2026:3948 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-1190 vdb-entry
- RHBZ#2430835 issue-tracking