GHSA-h4wv-g838-66g3
Keycloak: Application-Level DoS via Scope Processing
At a glance
- Published
- Updated
- CVE
- CVE-2026-4634
- Aliases
- BIT-keycloak-2026-4634
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
Affected packages
| Package | Versions |
|---|---|
| Maven · org.keycloak:keycloak-services | introduced 0, fixed 26.5.7 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-4634 ADVISORY
- https://github.com/keycloak/keycloak/issues/47716 WEB
- https://github.com/keycloak/keycloak/commit/b455ee4f28abb6f2120aff72fd179589cc5267a0 WEB
- https://access.redhat.com/errata/RHSA-2026:6475 WEB
- https://access.redhat.com/errata/RHSA-2026:6476 WEB
- https://access.redhat.com/errata/RHSA-2026:6477 WEB
- https://access.redhat.com/errata/RHSA-2026:6478 WEB
- https://access.redhat.com/security/cve/CVE-2026-4634 WEB
- https://bugzilla.redhat.com/show_bug.cgi?id=2450250 WEB
- https://github.com/keycloak/keycloak PACKAGE
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |