CVE-2026-4634 is a high-severity denial-of-service (DoS) vulnerability affecting Keycloak, where an unauthenticated attacker can exhaust server resources. This is achieved by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. Rated 7.5 CVSS, this flaw has a low attack complexity and requires no user interaction, leading to prolonged processing times and service disruption. Currently, there is no evidence of active exploitation, nor are public exploit codes available in Metasploit, Nuclei, or ExploitDB. Community discussion regarding this CVE remains minimal.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
Range not provided by sourceCPE matchmatch criteria | cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:text-only:*:*:* | ||
26.2CPE matchmatch criteria | cpe:2.3:a:redhat:build_of_keycloak:26.2:*:*:*:text-only:*:*:* | ||
26.2.15CPE matchmatch criteria | cpe:2.3:a:redhat:build_of_keycloak:26.2.15:*:*:*:text-only:*:*:* | ||
26.4CPE matchmatch criteria | cpe:2.3:a:redhat:build_of_keycloak:26.4:*:*:*:text-only:*:*:* | ||
26.4.11CPE matchmatch criteria | cpe:2.3:a:redhat:build_of_keycloak:26.4.11:*:*:*:text-only:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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