GitHub Advisoryadvisory · Maven
GHSA-m6qj-3mpp-57v8 Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise
MEDIUM
Official page ↗
- Aliases
- CVE-2026-9087
- Ecosystem
- Maven
- Packages
- org.keycloak:keycloak-services
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-639
- Reviewed
- 2026-06-11
Affected packages
• Maven org.keycloak:keycloak-services: < 26.6.3 → fixed in 26.6.3
Description
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.
Related
Alias · CVE (1)
- CVE-2026-9087 A flaw was found in Keycloak. vulnerability
Weakness · CWE (1)
- CWE-639 Authorization Bypass Through User-Controlled Key weakness
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-9087 advisory
- https://github.com/keycloak/keycloak/commit/37dabf59d0b5ca3e5b3b272bcd3b2580e67b94dd web
- https://access.redhat.com/errata/RHSA-2026:25097 web
- https://access.redhat.com/errata/RHSA-2026:25098 web
- https://access.redhat.com/errata/RHSA-2026:30049 web
- https://access.redhat.com/errata/RHSA-2026:30050 web
- https://access.redhat.com/security/cve/CVE-2026-9087 web
- https://bugzilla.redhat.com/show_bug.cgi?id=2480172 web
- https://github.com/keycloak/keycloak package
- https://github.com/keycloak/keycloak/releases/tag/26.6.3 web