CVE-2026-18215

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 v3 6.8 MEDIUM

6.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-18215
https://bugzilla.redhat.com/show_bug.cgi?id=2508309

Configurations

No configuration.

History

31 Jul 2026, 08:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-31 08:16

Updated : 2026-07-31 11:17

NVD link : CVE-2026-18215

Mitre link : CVE-2026-18215

CVE.ORG link : CVE-2026-18215

JSON object : View

Products Affected

No product.

CWE

CWE-287

Improper Authentication

{"id": "CVE-2026-18215", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-18215", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-07-31T11:00:33.369953Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "secalert@redhat.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.8, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 1.6}]}, "affected": [{"source": "secalert@redhat.com", "affectedData": [{"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "rhbk-keycloak-rhel9/rhbk-keycloak-rhel9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:build_keycloak:"], "vendor": "Red Hat", "product": "Red Hat Build of Keycloak", "packageName": "rhbk-openshift-rhel9/rhbk-openshift-rhel9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:jboss_data_grid:8"], "vendor": "Red Hat", "product": "Red Hat Data Grid 8", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:jbosseapxp"], "vendor": "Red Hat", "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/a:redhat:red_hat_single_sign_on:7"], "vendor": "Red Hat", "product": "Red Hat Single Sign-On 7", "packageName": "keycloak-services", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}]}], "published": "2026-07-31T08:16:27.893", "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-18215", "source": "secalert@redhat.com"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2508309", "source": "secalert@redhat.com"}], "vulnStatus": "Received", "weaknesses": [{"type": "Secondary", "source": "secalert@redhat.com", "description": [{"lang": "en", "value": "CWE-287"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-07-31T11:17:06.607", "sourceIdentifier": "secalert@redhat.com"}