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CVE-2026-4634

Last refreshed2026-10-06

Status: UPDATED  |  Advisory ID: CVE-2026-4634

Key Details

CVECVE-2026-4634
CVSS Score / Version7.5 (High) / CVSS v3.1
Updated2026-10-06
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Proseattack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is none; integrity impact is none; availability impact is high.
Affected productsRed Hat Build of Keycloak, Red Hat RHEL-8 based Middleware Containers, Red Hat build of Keycloak 26.2, and Red Hat build of Keycloak 26.4
Classified asCWE-1050 (Excessive Platform Resource Consumption within a Loop)

Affected Products, Subsystems & Sectors

VendorProductAffected VersionsPatch Status
Red HatRed Hat Build of Keycloak
Red HatRHEL-8 based Middleware Containers
Red HatRed Hat build of Keycloak 26.2
Red HatRed Hat build of Keycloak 26.4
SubsystemsOT Supporting Infrastructure
SectorsMultiple

What to Know

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. (NVD)

What to Do

Monitor Red Hat's web page for any future patch releases. See vendor advisory link below.

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-4634
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-4634
Vendor advisoryhttps://access.redhat.com/errata/RHSA-2026:6475