---
id: CVE-2026-105301
title: >-
  A flaw was found in the X.509 client-certificate authenticator of Keycloak, a
  solution for identity and access management
summary: >-
  A flaw was found in the X.509 client-certificate authenticator of Keycloak, a
  solution for identity and access management. The issue occurs when the server
  is configured to check certificate revocation using CRL Distribution Points or
  OC…
severity: medium
cvss: 4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N'
cwe:
  - CWE-918
vendor: Red Hat
product: keycloak-services
affected:
  - keycloak-services (all versions)
  - rhbk/keycloak-rhel9 (all versions)
  - keycloak-services
published: '2026-10-05'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T06:16:58.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-105301'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-105301'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2545797'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-105301.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-105301'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-105301'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-10-05T06:13:49.198Z'
---

## Overview

A flaw was found in the X.509 client-certificate authenticator of Keycloak, a solution for identity and access management. The issue occurs when the server is configured to check certificate revocation using CRL Distribution Points or OCSP. An attacker can provide a specially crafted certificate that points to a malicious server, causing Keycloak to make unauthorized outbound requests to internal or external endpoints before the certificate is fully validated. This can lead to a blind server-side request forgery (SSRF) attack.

## 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 2026-10-05 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-105301.json)