6.8
Medium
CVE-2026-9704 A flaw was found in Keycloak
Description
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Build of Keycloak | Versions not published | |
| Red Hat build of Keycloak 26.6.3 | Versions not published | |
| Red Hat build of Keycloak 26.6 26.6 | earliest → < 26.6-6 | 26.6-6 |
| Red Hat build of Keycloak 26.6.4 | Versions not published | |
| Red Hat build of Keycloak 26.4 26.4 | earliest → < 26.4-19 | 26.4-19 |
| Red Hat build of Keycloak 26.4.13 | Versions not published |
Other CVEs of Red Hat Build of Keycloak
The 277 CVEs of Red Hat Build of Keycloak →
CVE-2026-120984
Keycloak-services: keycloak-services: manage-clients to arbitrary code execution through inline javascript policy import
9.1
Critical
CVE-2026-9797
Keycloak: keycloak: privilege escalation via client authentication manipulation by an authenticated administrator
6.5
Medium
CVE-2026-97848
Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sanitization
6.5
Medium
CVE-2026-97367
Keycloak-services: keycloak-services: dcr azp and sid claim substitution allows account rest session takeover
6.4
Medium