CVE-2026-18215 — MEDIUM (6.8)

Vulnerability 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.

CVSS Score

6.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

NONE

Affected Products

Vendor	Product	Versions
Redhat	Build Of Keycloak	-

Related Weaknesses (CWE)

CWE-287

References

https://access.redhat.com/security/cve/CVE-2026-18215Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2508309Issue TrackingVendor Advisory

FAQ

What is CVE-2026-18215?

CVE-2026-18215 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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 th...

How severe is CVE-2026-18215?

CVE-2026-18215 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-18215?

Check the references section above for vendor advisories and patch information. Affected products include: Redhat Build Of Keycloak.