CVE-2026-9689

MEDIUM

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

Title source: cna
STIX 2.1

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.

References (2)

Core 2
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-9689
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2481845
https://bugzilla.redhat.com/show_bug.cgi?id=2481845

Scores

CVSS v3 4.2
EPSS 0.0021
EPSS Percentile 11.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-1288
Status published
Products (4)
org.keycloak/keycloak-services 0 - 26.4.7Maven
org.keycloak/keycloak-services 26.5.0 - 26.6.4Maven
Red Hat/Red Hat Build of Keycloak
redhat/build_of_keycloak
Published May 27, 2026
Tracked Since May 27, 2026