CVE-2026-18215

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-31 08:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-16 19:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-07-31 08:16 UTC

Last modified

2026-09-16 19:17 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-287 · Improper authentication

Record status

Modified

Affected

• Redhat Build Of Keycloak

Attack profile CVSS 3.1 · 6.8

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-18215.md and follow it. Check whether this project is affected by CVE-2026-18215. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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