Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-16093
Red Hat Red Hat build of Keycloak 26.6 — Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L L N U L L N 5.4 .0039 31.2 —
AFFECTED
Product Versions Fixed
Red Hat build of Keycloak 26.6 unspecified 26.6.7-3
Red Hat build of Keycloak 26.6 unspecified 26.6-20
Red Hat build of Keycloak 26.6 unspecified 26.6-20
Red Hat build of Keycloak 26.6.7 unspecified —
Red Hat build of Keycloak 26.6.7 unspecified —
Red Hat build of Keycloak 26.6.7 unspecified —
Red Hat Data Grid 8 unspecified —
Red Hat JBoss Enterprise Application Platform Expansion Pack unspecified —
Red Hat Single Sign-On 7 unspecified —
TIMELINE
Jul 17 Reserved by redhat
Jul 17 Published (CNA: redhat)
Sep 16 PATCH SHIPPED — CVE-2026-16093 (Red Hat build of Keycloak 26.6). Fixed in Red Hat build of Keycloak 26.6 26.6.7-3.
Description
Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker with valid client credentials can provide a fake, unsigned assertion header that tricks the system into thinking the policy requirements have been met. This allows the attacker to authenticate using simpler methods like a client secret even when the administrator has mandated more secure, signed assertions.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 17, 2026 | Reserved | Reserved by redhat |
| July 17, 2026 | Published | Published (CNA: redhat) |
| September 16, 2026 | PATCH SHIPPED | PATCH SHIPPED — CVE-2026-16093 (Red Hat build of Keycloak 26.6). Fixed in Red Hat build of Keycloak 26.6 26.6.7-3. |
Affected
Affected products and packages — 9 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Red Hat | Red Hat build of Keycloak 26.6 | — | — | 26.6.7-3 |
| Red Hat | Red Hat build of Keycloak 26.6 | — | — | 26.6-20 |
| Red Hat | Red Hat build of Keycloak 26.6 | — | — | 26.6-20 |
| Red Hat | Red Hat build of Keycloak 26.6.7 | — | — | — |
| Red Hat | Red Hat build of Keycloak 26.6.7 | — | — | — |
| Red Hat | Red Hat build of Keycloak 26.6.7 | — | — | — |
| Red Hat | Red Hat Data Grid 8 | — | — | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — | — |
| Red Hat | Red Hat Single Sign-On 7 | — | — | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-16093 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
