CVE-2026-9689 (GCVE-0-2026-9689)

Vulnerability from cvelistv5 – Published: 2026-05-27 10:35 – Updated: 2026-05-27 14:46
VLAI
Title
Keycloak: org.keycloak.protocol.oidc: http parameter pollution in oidc redirect uri allows response parameter duplication - #ghi-604
Summary
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.
Severity
4.2 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-1288 - Improper Validation of Consistency within Input
Assigner
References
URL Tags
https://access.redhat.com/security/cve/CVE-2026-9689 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2481845 issue-trackingx_refsource_REDHAT
Impacted products
Vendor Product Version
Red Hat Red Hat Build of Keycloak     cpe:/a:redhat:build_keycloak:
 Create a notification for this product.
Date Public
2026-05-27 10:18
Credits
Red Hat would like to thank Martin Bartoš for reporting this issue.
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.