---
id: CVE-2026-97846
title: >-
  Keycloak provides a feature called mTLS holder-of-key binding which ensures
  that a token can only be used by the client that originally requested it by
  binding it to their digital certificate
summary: >-
  Keycloak provides a feature called mTLS holder-of-key binding which ensures
  that a token can only be used by the client that originally requested it by
  binding it to their digital certificate. A flaw was discovered where the new
  Standard…
severity: medium
cvss: 6.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-287
vendor: Red Hat
product: Red Hat Build of Keycloak
affected:
  - build_of_keycloak
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T07:16:57.147'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97846'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-97846'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2540949'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97846.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97846'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97846'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
ingestedAt: '2026-09-25T07:01:12.116Z'
---

## Overview

Keycloak provides a feature called mTLS holder-of-key binding which ensures that a token can only be used by the client that originally requested it by binding it to their digital certificate. A flaw was discovered where the new Standard Token Exchange V2 feature does not check for this certificate. This allows an attacker with stolen client credentials to obtain a standard, unrestricted token that bypasses these security protections.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Build of Keycloak · no fix planned: Red Hat Build of Keycloak · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97846.json)