A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject_token JSON Web Token (JWT) to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client credentials. This allows the user to gain the permissions of the client's service account, leading to privilege escalation.
References
| Link | Resource |
|---|---|
| https://access.redhat.com/errata/RHSA-2026:25097 | |
| https://access.redhat.com/errata/RHSA-2026:25098 | |
| https://access.redhat.com/security/cve/CVE-2026-9704 | Mitigation Vendor Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2481877 | Issue Tracking Vendor Advisory |
Configurations
History
10 Jun 2026, 22:17
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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10 Jun 2026, 18:17
| Type | Values Removed | Values Added |
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| References |
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03 Jun 2026, 15:40
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:* | |
| References | () https://access.redhat.com/security/cve/CVE-2026-9704 - Mitigation, Vendor Advisory | |
| References | () https://bugzilla.redhat.com/show_bug.cgi?id=2481877 - Issue Tracking, Vendor Advisory | |
| First Time |
Redhat
Redhat build Of Keycloak |
27 May 2026, 14:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-27 14:17
Updated : 2026-06-10 22:17
NVD link : CVE-2026-9704
Mitre link : CVE-2026-9704
CVE.ORG link : CVE-2026-9704
JSON object : View
Products Affected
redhat
- build_of_keycloak
CWE
CWE-1284
Improper Validation of Specified Quantity in Input