CVE-2026-9689

Keycloak: org.keycloak.protocol.oidc: http parameter pollution in oidc redirect uri allows response parameter duplication - #ghi-604

State
Published
Severity
4.2 Medium
Published
May 27, 2026
Updated
Aug 20, 2026
Reserved
May 27, 2026

Read the record on cve.org

Description

A flaw was found in Keycloak, an open-source identity and access management solution. When a client application is configured to accept broad redirect Uniform Resource Identifiers (URIs), a remote attacker can manipulate the authentication process by crafting a special web address. If a user clicks this link, the client application might incorrectly prioritize attacker-controlled information over legitimate data. This vulnerability, known as HTTP parameter pollution, could allow an attacker to bypass security measures or gain unauthorized access to resources.

Scores

CVSSScoreVectorSource
3.14.2 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:Nredhat

Weaknesses

  • CWE-1288 Improper Validation of Consistency within Input

Affected Products

ProductVersions
Red Hat build of Keycloak 26.4Red Hat
  • 26.4.14-1 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat
  • 26.4-22 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat
  • 26.4-22 and laterNot affected
Red Hat build of Keycloak 26.4.14Red Hat
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6.5-1 and laterNot affected
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6-11 and laterNot affected
    Red Hat build of Keycloak 26.6Red Hat
    • 26.6-11 and laterNot affected
    Red Hat build of Keycloak 26.6.5Red Hat

      References

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