Disclosure summary
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.
Source-reported weakness categories
CWE-1050
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2026-4634
Open original source · Updated Oct 06, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| redhat | build_of_keycloak | - |
| redhat | build_of_keycloak | 26.2 |
| redhat | build_of_keycloak | 26.2.15 |
| redhat | build_of_keycloak | 26.4 |
| redhat | build_of_keycloak | 26.4.11 |
Original records & references
- NIST NVD record
- CVE Program record
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com — Vendor Advisory
- bugzilla.redhat.com — Issue Tracking, Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- access.redhat.com — Vendor Advisory
- bugzilla.redhat.com — Issue Tracking, Vendor Advisory
- security.access.redhat.com
PUBLISHED 2026-04-02T09:16:27-04:00
MODIFIED 2026-10-06T13:17:26-04:00
INGESTED 2026-10-08T12:40:21-04:00