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CVE-2026-9087

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

Published: May 20, 2026Updated: Jul 23, 2026 Sources: CVE List NVDCWE-639
6.4MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 76.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:LUI:RS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-639

Affected Products

Red Hat
commercial·USaka redhat
Red Hat build of Keycloak 26.4On-premWeb App
Web & CMS Plugins
Red Hat build of Keycloak 26.4.13On-prem
DevTools & CI
Red Hat build of Keycloak 26.6On-prem
Security Products / identity-access-mgmt
Red Hat build of Keycloak 26.6.3On-prem
Security Products / identity-access-mgmt
build of keycloakOn-prem
Operating Systems / linux-distro

Exploitability

Official Patch Available
Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://access.redhat.com/errata/RHSA-2026:25097
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:25098
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:30049
access.redhat.com
and 3 more references View all →

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