CVE-2026-18215

highpriority · track · 32EPSS 0.004 · 34 %ileDEEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.40% (34th) EPSS
CVSS 8.1 · high
Is it mine?
3 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-27

Keycloak provides a way to let users log in using Microsoft accounts while restricting access to a specific organization (tenant). A flaw was discovered where this restriction is ignored when using the token exchange feature. This means an attacker with a valid Microsoft token from a completely different organization could gain access to the Keycloak realm, potentially accessing sensitive data or performing unauthorized actions.

01

cvss

Technical severity, 0–10. One row per scoring source.

8.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.8–8.1

v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 5.2
v3.16.8mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Nsecondary · ENISA EU
v3.16.8mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Nsecondary · secalert@redhat.com USexploitability 1.6 · impact 5.2
v3.17.4highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-287US
04

affected products (3)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-2614Keycloak: Mehrere SchwachstellenDeutsch2026-08-02csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Keycloak ausnutzen, um seine Privilegien zu erhöhen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren und sensible Informationen offenzulegen.

  • BIT-keycloak-2026-18215Keycloak-services: keycloak-services: microsoft external access-token exchange bypasses configured tenant2026-08-31vendor · osvUS

    Keycloak provides a way to let users log in using Microsoft accounts while restricting access to a specific organization (tenant). A flaw was discovered where this restriction is ignored when using the token exchange feature. This means an attacker with a valid Microsoft token from a completely different organization could gain access to the Keycloak realm, potentially accessing sensitive data or performing unauthorized actions.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdcert_bundnvdosvNVDCVE.orgMITRE
published 2026-07-31modified 2026-09-16
08

references (8)

External citations — patches, advisories, analysis.

scry

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