CVE-2026-9087 | BDVDB-2026-334142 Detail

Red HatRed Hat build of Keycloak 26.4

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.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact none. Attack vector: network.

Weaknesses#

CWE-639 Authorization Bypass Through User-Controlled Key

References#

Exploit#

No public exploit known

History#

Version 12026-05-20Record published in the CVE List.
Version 22026-08-03Most recent update recorded in the CVE List.

Published

Published: 2026-05-20
Last modified: 2026-08-03

Vendor information

Vendor: Red Hat
Product: Red Hat build of Keycloak 26.4

All Red Hat vulnerabilities

Score

6.4 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 24.2.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Insecure Direct Object Reference

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
Not stated
Fixed
26.4.13-1
Vulnerable
Not stated
Fixed
26.4-19

Scoring System

CVSS v4.0

Not available

CVSS v3.1

6.4 Medium

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

Metric breakdown
Attack Vector	Network
Attack Complexity	High
Privileges Required	Low
User Interaction	Required
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).