---
id: CVE-2026-90997
title: A flaw was found in Keycloak
summary: >-
  A flaw was found in Keycloak. When deployed in stateless mode with MySQL or
  MariaDB, a mismatch in row-count semantics between the database driver and
  Keycloak's application logic allows an attacker to bypass replay protection.
  This vuln…
severity: high
cvss: 7.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-294
vendor: Keycloak
product: keycloak-services
affected:
  - keycloak-services >= 26.7.0 < 26.7.4
  - rhbk/keycloak-rhel9
  - rhbk/keycloak-rhel9-operator
published: '2026-09-17'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T19:16:56.183'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90997'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-90997'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533141'
    label: secalert@redhat.com
  - url: 'https://github.com/keycloak/keycloak'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90997.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-90997'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90997'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-21T21:07:40.908040Z'
epss: 0.00396
epssPercentile: 0.33692
ingestedAt: '2026-09-17T19:26:25.319Z'
---

## Overview

A flaw was found in Keycloak. When deployed in stateless mode with MySQL or MariaDB, a mismatch in row-count semantics between the database driver and Keycloak's application logic allows an attacker to bypass replay protection. This vulnerability enables an attacker who intercepts single-use security artifacts, such as JWT client assertions, DPoP proofs, or one-time password (TOTP) codes, to replay them. Successful exploitation grants unauthorized access to the token endpoint or login flow.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90997.json)