CVE-2026-4634
Last modified
CVE-2026-4634 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.52% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Redhat | Build Of Keycloak | All versions |
| 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 |
References
- https://access.redhat.com/errata/RHSA-2026:6475Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6476Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6477Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6478Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-4634Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2450250Issue Tracking, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6475Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6476Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6477Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:6478Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-4634Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2450250Issue Tracking, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
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