7.5
High
CVE-2026-4634 A flaw was found in Keycloak
Description
A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Build of Keycloak | Versions not published | |
| Red Hat build of Keycloak 26.4 26.4 | earliest → < 26.4-14 | 26.4-14 |
| Red Hat build of Keycloak 26.4.11 | Versions not published | |
| Red Hat build of Keycloak 26.2 26.2 | earliest → < 26.2-18 | 26.2-18 |
| Red Hat build of Keycloak 26.2.15 | Versions not published | |
| Red Hat Single Sign-On 7 | Versions not published | |
| Red Hat Single Sign-On 7.6.13 | Versions not published | |
| RHEL-8 based Middleware Containers 7.6 | earliest → < 7.6-85 | 7.6-85 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | Versions not published |
Show the 2 other branches Hide the 2 other branches
| Product | Affected versions | Fixed in |
|---|---|---|
| Red Hat Single Sign-On 7.6 for RHEL 9 | Versions not published | |
| Red Hat Single Sign-On 7.6 for RHEL 7 | Versions not published |
References
- RHSA-2026:6475 access.redhat.com
- RHSA-2026:6476 access.redhat.com
- RHSA-2026:6477 access.redhat.com
- RHSA-2026:6478 access.redhat.com
- RHSA-2026:76128 access.redhat.com
- RHSA-2026:76129 access.redhat.com
- RHSA-2026:76130 access.redhat.com
- RHSA-2026:76132 access.redhat.com
- RHSA-2026:76134 access.redhat.com
- access.redhat.com access.redhat.com
- RHBZ#2450250 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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Keycloak-services: keycloak-services: unverified idp email auto-linking enables account takeover
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CVE-2026-97174
Keycloak-services: keycloak-services: ciba sub parameter injection causes attacker authentication to issue victim tokens
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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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