Vulnerability in Red Hat Build Of Keycloak 26.2
CVE-2026-4634
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 r…
EPSS: 0.000 (7.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Red Hat Build Of Keycloak 26.2 — versions 26.2.15-1, 26.2-18
- Red Hat Build Of Keycloak 26.2.15
- Red Hat Build Of Keycloak 26.4 — versions 26.4.11-1, 26.4-14
- Red Hat Build Of Keycloak 26.4.11
Weakness classification (CWE)
References
- RHSA-2026:6475 (vendor-advisory, x_refsource_REDHAT)
- RHSA-2026:6476 (vendor-advisory, x_refsource_REDHAT)
- RHSA-2026:6477 (vendor-advisory, x_refsource_REDHAT)
- RHSA-2026:6478 (vendor-advisory, x_refsource_REDHAT)
- access.redhat.com/security/cve/CVE-2026-4634 (vdb-entry, x_refsource_REDHAT)
- RHBZ#2450250 (issue-tracking, x_refsource_REDHAT)
Frequently asked questions
- What is CVE-2026-4634?
- CVE-2026-4634 is a high-severity vulnerability in Red Hat Build Of Keycloak 26.2, classified under CWE-1050. CVSS score: 7.5/10. Published 2026-04-02.
- How severe is CVE-2026-4634?
- High severity. CVSS v3 base score is 7.5 out of 10.