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 |
References
- RHSA-2026:25097 access.redhat.com
- RHSA-2026:25098 access.redhat.com
- RHSA-2026:30049 access.redhat.com
- RHSA-2026:30050 access.redhat.com
- access.redhat.com access.redhat.com
- RHBZ#2481877 bugzilla.redhat.com
Timeline
- Published
- Last modified
Other CVEs of Red Hat Build of Keycloak
The 266 CVEs of Red Hat Build of Keycloak →
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CVE-2026-97174
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CVE-2026-96453
Org.keycloak/keycloak-admin-cli: keycloak-admin-cli: kcadm custom truststore accepts arbitrary self-signed certificates
8.0
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