Medium 6.4Published May 20, 2026

CVE-2026-9087Keycloak: cross-session email verification proof not bound to upstream identity in first-broker-login

Updated under an hour ago (Oct 26, 2026, 4:30 PM ET)

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It affects Red Hat build of Keycloak 26.4 and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Red Hat build of Keycloak 26.4

Exploited in the last 30 days

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.

CVSS: 6.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-639
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: redhat
NVD analysis: Modified
Record last updated: Aug 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Red Hat Red Hat build of Keycloak 26.4 redhat:build_keycloak	from 26.4.13-1 not affected	CNA record
redhat build_of_keycloak redhat:build_of_keycloak	all versions	NVD

References

References

https://access.redhat.com/errata/RHSA-2026:25097	vendor-advisory, x-refsource-redhat
https://access.redhat.com/errata/RHSA-2026:25098	vendor-advisory, x-refsource-redhat
https://access.redhat.com/errata/RHSA-2026:30049	vendor-advisory, x-refsource-redhat
https://access.redhat.com/errata/RHSA-2026:30050	vendor-advisory, x-refsource-redhat
https://access.redhat.com/security/cve/CVE-2026-9087	vdb-entry, x-refsource-redhat, vendor-advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2480172	issue-tracking, x-refsource-redhat, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.