CVE-2026-4636 (GCVE-0-2026-4636)

Vulnerability from cvelistv5 – Published: 2026-04-02 12:45 – Updated: 2026-04-02 16:35
VLAI?
Title
Keycloak: keycloak: uma policy bypass allows authenticated users to gain unauthorized access to victim-owned resources.
Summary
A flaw was found in Keycloak. An authenticated user with the uma_protection role can bypass User-Managed Access (UMA) policy validation. This allows the attacker to include resource identifiers owned by other users in a policy creation request, even if the URL path specifies an attacker-owned resource. Consequently, the attacker gains unauthorized permissions to victim-owned resources, enabling them to obtain a Requesting Party Token (RPT) and access sensitive information or perform unauthorized actions.
Severity ?
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CWE
  • CWE-551 - Incorrect Behavior Order: Authorization Before Parsing and Canonicalization
Assigner
References
https://access.redhat.com/errata/RHSA-2026:6475 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:6476 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:6477 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:6478 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-4636 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2450251 issue-trackingx_refsource_REDHAT
Impacted products
Vendor Product Version
Red Hat Red Hat build of Keycloak 26.2 Unaffected: 26.2.15-1 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.2::el9
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    Red Hat Red Hat build of Keycloak 26.2 Unaffected: 26.2-18 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.2::el9
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    Red Hat Red Hat build of Keycloak 26.2 Unaffected: 26.2-18 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.2::el9
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    Red Hat Red Hat build of Keycloak 26.2.15     cpe:/a:redhat:build_keycloak:26.2::el9
 Create a notification for this product.
    Red Hat Red Hat build of Keycloak 26.4 Unaffected: 26.4.11-1 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
    Red Hat Red Hat build of Keycloak 26.4 Unaffected: 26.4-14 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
    Red Hat Red Hat build of Keycloak 26.4 Unaffected: 26.4-14 , < * (rpm)
    cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
    Red Hat Red Hat build of Keycloak 26.4.11     cpe:/a:redhat:build_keycloak:26.4::el9
 Create a notification for this product.
Date Public ?
2026-04-02 12:30
Show details on NVD website
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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.



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