Vulnerability Details CVE-2026-9086
A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with `manage-client` permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive `javascript:` or `data:` scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.004
EPSS Ranking 34.0%
CVSS Severity
CVSS v3 Score 7.3
References
- https://access.redhat.com/errata/RHSA-2026:30049
- https://access.redhat.com/errata/RHSA-2026:30050
- https://access.redhat.com/errata/RHSA-2026:30083
- https://access.redhat.com/errata/RHSA-2026:30084
- https://access.redhat.com/security/cve/CVE-2026-9086
- https://bugzilla.redhat.com/show_bug.cgi?id=2480170
- https://access.redhat.com/errata/RHSA-2026:30049
- https://access.redhat.com/errata/RHSA-2026:30050
- https://access.redhat.com/errata/RHSA-2026:30083
- https://access.redhat.com/errata/RHSA-2026:30084
- https://access.redhat.com/security/cve/CVE-2026-9086
- https://bugzilla.redhat.com/show_bug.cgi?id=2480170
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-9086.json
Products affected by CVE-2026-9086
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cpe:2.3:a:redhat:build_of_keycloak:26.4
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cpe:2.3:a:redhat:build_of_keycloak:26.4.10
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cpe:2.3:a:redhat:build_of_keycloak:26.4.11
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cpe:2.3:a:redhat:build_of_keycloak:26.4.12
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cpe:2.3:a:redhat:build_of_keycloak:26.4.4
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cpe:2.3:a:redhat:build_of_keycloak:26.4.5
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cpe:2.3:a:redhat:build_of_keycloak:26.4.6
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cpe:2.3:a:redhat:build_of_keycloak:26.4.7
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cpe:2.3:a:redhat:build_of_keycloak:26.4.8
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cpe:2.3:a:redhat:build_of_keycloak:26.4.9
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cpe:2.3:a:redhat:build_of_keycloak:26.6
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cpe:2.3:a:redhat:build_of_keycloak:26.6.3