CVE-2026-4634 is a high-severity security vulnerability in org.keycloak:keycloak-services (maven), affecting versions < 26.5.7. It is fixed in 26.5.7.
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.
CVE-2026-4634 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (26.5.7). Upgrading removes the vulnerable code path.
maven
org.keycloak:keycloak-services (< 26.5.7)org.keycloak:keycloak-services → 26.5.7 (maven)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-4634 is reachable in your applications. Explore open-source security for your team.
See if CVE-2026-4634 is reachable in your applications. Get a demo
Already deployed Kodem? See CVE-2026-4634 in your environment →Upgrade org.keycloak:keycloak-services to 26.5.7 or later to resolve this vulnerability.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-4634 is a high-severity security vulnerability in org.keycloak:keycloak-services (maven), affecting versions < 26.5.7. It is fixed in 26.5.7.
CVE-2026-4634 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
org.keycloak:keycloak-services (maven) versions < 26.5.7 is affected.
Yes. CVE-2026-4634 is fixed in 26.5.7. Upgrade to this version or later.
Whether CVE-2026-4634 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade org.keycloak:keycloak-services to 26.5.7 or later.