CVE-2026-9689 — Keycloak: org.keycloak.protocol.oidc: http parameter pollution in oidc redirect uri allows response parameter duplication - #ghi-604
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 Identifie…
Published: 2026-05-27 · CVSS: 4.2 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7