CVE-2026-9087 is a medium-severity security vulnerability in org.keycloak:keycloak-services (maven), affecting versions < 26.6.3. It is fixed in 26.6.3.
A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId, idpAlias) and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account.
CVE-2026-9087 has a CVSS score of 6.4 (Medium). The vector is network-reachable, low privileges required, and user interaction required. 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 (26.6.3). Upgrading removes the vulnerable code path.
maven
org.keycloak:keycloak-services (< 26.6.3)org.keycloak:keycloak-services → 26.6.3 (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-2026-9087 is reachable in your applications. Explore open-source security for your team.
See if CVE-2026-9087 is reachable in your applications. Get a demo
Already deployed Kodem? See CVE-2026-9087 in your environment →Upgrade org.keycloak:keycloak-services to 26.6.3 or later to resolve this vulnerability.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-9087 is a medium-severity security vulnerability in org.keycloak:keycloak-services (maven), affecting versions < 26.6.3. It is fixed in 26.6.3.
CVE-2026-9087 has a CVSS score of 6.4 (Medium). 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 < 26.6.3 is affected.
Yes. CVE-2026-9087 is fixed in 26.6.3. Upgrade to this version or later.
Whether CVE-2026-9087 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 26.6.3 or later.