5.3
Medium
CVE-2026-9803 A flaw was found in Keycloak's ClientRegistrationAuth component
Description
A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.
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#2482465 bugzilla.redhat.com
Timeline
- Published
- Last modified
Other CVEs of Red Hat Build of Keycloak
The 275 CVEs of Red Hat Build of Keycloak →
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CVE-2026-97367
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CVE-2026-96547
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CVE-2026-96460
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5.4
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