CVE-2026-4634 | BDVDB-2026-324301 Detail
Red HatRed Hat build of Keycloak 26.2
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.
Impact#
Per CVSS v3.1: confidentiality impact none, integrity impact none, availability impact high. Attack vector: network.
Weaknesses#
- CWE-1050 Excessive Platform Resource Consumption within a Loop
References#
- https://access.redhat.com/errata/RHSA-2026:6475
- https://access.redhat.com/errata/RHSA-2026:6476
- https://access.redhat.com/errata/RHSA-2026:6477
- https://access.redhat.com/errata/RHSA-2026:6478
- https://access.redhat.com/errata/RHSA-2026:76128
- https://access.redhat.com/errata/RHSA-2026:76129
- https://access.redhat.com/errata/RHSA-2026:76130
- https://access.redhat.com/errata/RHSA-2026:76132
- https://access.redhat.com/errata/RHSA-2026:76134
- https://access.redhat.com/security/cve/CVE-2026-4634
- https://bugzilla.redhat.com/show_bug.cgi?id=2450250
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4634.json
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.