Origin Validation Error Affecting keycloak-doc package, versions <26.6.0-r0


Severity

Recommended
0.0
low
0
10

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Threat Intelligence

EPSS
0.01% (1st percentile)

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  • Snyk IDSNYK-MINIMOSLATEST-KEYCLOAKDOC-15983865
  • published12 Apr 2026
  • disclosed6 Apr 2026

Introduced: 6 Apr 2026

NewCVE-2026-37977  (opens in a new tab)
CWE-346  (opens in a new tab)

How to fix?

Upgrade Minimos:latest keycloak-doc to version 26.6.0-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream keycloak-doc package and not the keycloak-doc package as distributed by Minimos. See How to fix? for Minimos:latest relevant fixed versions and status.

A flaw was found in Keycloak. A remote attacker can exploit a Cross-Origin Resource Sharing (CORS) header injection vulnerability in Keycloak's User-Managed Access (UMA) token endpoint. This flaw occurs because the azp claim from a client-supplied JSON Web Token (JWT) is used to set the Access-Control-Allow-Origin header before the JWT signature is validated. When a specially crafted JWT with an attacker-controlled azp value is processed, this value is reflected as the CORS origin, even if the grant is later rejected. This can lead to the exposure of low-sensitivity information from authorization server error responses, weakening origin isolation, but only when a target client is misconfigured with webOrigins: [&#34;*&#34;].

CVSS Base Scores

version 3.1