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-2026-18215
Red Hat Red Hat build of Keycloak 26.6 — Keycloak-services: keycloak-services: microsoft external access-token exchange bypasses configured tenant
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L L N U H H N 8.1 .0040 32.3 —
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 29 Reserved by redhat
Jul 31 Published (CNA: redhat)
Sep 16 PATCH SHIPPED — CVE-2026-18215 (Red Hat build of Keycloak 26.6). Fixed in Red Hat build of Keycloak 26.6 26.6.7-3.
Description
Keycloak provides a way to let users log in using Microsoft accounts while restricting access to a specific organization (tenant). A flaw was discovered where this restriction is ignored when using the token exchange feature. This means an attacker with a valid Microsoft token from a completely different organization could gain access to the Keycloak realm, potentially accessing sensitive data or performing unauthorized actions.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 29, 2026 | Reserved | Reserved by redhat |
| July 31, 2026 | Published | Published (CNA: redhat) |
| September 16, 2026 | PATCH SHIPPED | PATCH SHIPPED — CVE-2026-18215 (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-2026-18215 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.
