7.5

CVE-2026-4634

Keycloak: keycloak: denial of service via excessive processing of openid connect scope parameters

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Redhat ≫ Build Of Keycloak Version- SwEditiontext-only
Redhat ≫ Build Of Keycloak Version26.2 SwEditiontext-only
Redhat ≫ Build Of Keycloak Version26.2.15 SwEditiontext-only
Redhat ≫ Build Of Keycloak Version26.4 SwEditiontext-only
Redhat ≫ Build Of Keycloak Version26.4.11 SwEditiontext-only
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.52% 0.404
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
secalert@redhat.com 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
0b0ca135-0b70-47e7-9f44-1890c2a1c46c 7.5 3.9 3.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-1050 Excessive Platform Resource Consumption within a Loop

The product has a loop body or loop condition that contains a control element that directly or indirectly consumes platform resources, e.g. messaging, sessions, locks, or file descriptors.

https://access.redhat.com/security/cve/CVE-2026-4634
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2450250
Vendor Advisory
Issue Tracking
https://access.redhat.com/errata/RHSA-2026:6477
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6478
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6475
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6476
Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4634.json