CVE-2026-9087

MEDIUM

Keycloak: cross-session email verification proof not bound to upstream identity in first-broker-login

Title source: cna

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.

References (2)

Core 2

Core References

Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat

https://access.redhat.com/security/cve/CVE-2026-9087

Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat

RHBZ#2480172

https://bugzilla.redhat.com/show_bug.cgi?id=2480172

Scores

CVSS v3 6.4

EPSS 0.0003

EPSS Percentile 8.4%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-639

Status published

Products (1)

Red Hat/Red Hat Build of Keycloak

Published May 20, 2026

Tracked Since May 20, 2026