Skip to main content
← All vulnerabilities
CVE-2026-18209

Keycloak-services: keycloak-services: oidc redirect_uri fragment bypass in http parameter pollution check

Published
Last modified
published
Not listed in CISA KEV
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

A flaw was found in the keycloak-services component of Keycloak, which handles OpenID Connect (OIDC) authentication flows. The issue occurs because the security check designed to prevent HTTP parameter pollution only inspects the query portion of a redirect URL and ignores the fragment portion. When a client is configured with a wildcard redirect URI, an attacker can use this to inject duplicate security parameters into the login response. If a client application is not configured correctly, it might trust the attacker's injected data instead of the real security information from Keycloak, leading to session fixation or account confusion.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • rhbk/keycloak-operator-bundle

    Version range not reported

  • rhbk/keycloak-rhel9

    Version range not reported

  • rhbk/keycloak-rhel9-operator

    Version range not reported

  • keycloak-services

    Version range not reported

  • rhbk-keycloak-rhel9/rhbk-keycloak-rhel9

    Version range not reported

  • rhbk-openshift-rhel9/rhbk-openshift-rhel9

    Version range not reported

  • keycloak-services

    Version range not reported

  • keycloak-services

    Version range not reported

  • keycloak-services

    Version range not reported

References 4

access.redhat.com

bugzilla.redhat.com