CVE-2026-9087

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

20/05/2026

Last modified:

20/05/2026

Description

A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId,<br /> 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&#39;s local account.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 6.40 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): Required
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): None

Base Score 3.x

6.40

Severity 3.x

MEDIUM

References to Advisories, Solutions, and Tools

https://access.redhat.com/security/cve/CVE-2026-9087
https://bugzilla.redhat.com/show_bug.cgi?id=2480172