Vulnerability DatabaseCVE-2026-9087
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CVE-2026-9087
Published:May 20, 2026
Updated:June 11, 2026
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.
Affected Packages
org.keycloak:keycloak-services (JAVA):
Affected version(s) >=1.0-alpha-1 <26.6.3
Fix Suggestion:
Update to version 26.6.3
Related Resources (8)
https://access.redhat.com/security/cve/CVE-2026-9087
https://nvd.nist.gov/vuln/detail/CVE-2026-9087
https://access.redhat.com/errata/RHSA-2026:25098
https://bugzilla.redhat.com/show_bug.cgi?id=2480172
https://github.com/keycloak/keycloak/commit/37dabf59d0b5ca3e5b3b272bcd3b2580e67b94dd
https://github.com/keycloak/keycloak
https://access.redhat.com/errata/RHSA-2026:25097
https://github.com/keycloak/keycloak/releases/tag/26.6.3
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CVSS v4
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Authorization Bypass Through User-Controlled Key
CWE-639
EPSS
Base Score:
0.03