High7.3Red Hat Linux

High [CVE-2026-9086] Cross-site scripting (XSS) via case-insensitive URI validation bypass

This high-severity Red Hat Linux advisory covers CVE-2026-9086.

CVE-2026-9086 Published Jun 25, 2026Updated by vendor Jun 25, 2026

CVE-2026-9086

Affected products & platforms

Red Hat LinuxUnclassified

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Summary

Cross-site scripting (XSS) via case-insensitive URI validation bypass. Red Hat rates this important (CVSS 7.3).

Weakness: CWE-79. Red Hat lists fixing advisory RHSA-2026:30049 with package rhbk/keycloak-operator-bundle:26.4.13-1, rhbk/keycloak-rhel9-operator:26.4-19, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9:26.6-8.

Affected versions

rhbk/keycloak-operator-bundle:26.4.13-1
rhbk/keycloak-rhel9-operator:26.4-19
rhbk/keycloak-rhel9
rhbk/keycloak-rhel9:26.6-8
rhbk/keycloak-rhel9:26.4-19
rhbk/keycloak-operator-bundle:26.6.4-2
rhbk/keycloak-rhel9-operator:26.6-8

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Fixed versions

rhbk/keycloak-operator-bundle:26.4.13-1
rhbk/keycloak-rhel9-operator:26.4-19
rhbk/keycloak-rhel9
rhbk/keycloak-rhel9:26.6-8
rhbk/keycloak-rhel9:26.4-19
rhbk/keycloak-operator-bundle:26.6.4-2
rhbk/keycloak-rhel9-operator:26.6-8
RHSA-2026:30049

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

Mitigation checklist

Recommended fix / mitigation

To mitigate this vulnerability, restrict the ability to register new clients and manage existing client configurations. If Dynamic Client Registration is not required, disable it in Keycloak's Realm Settings under Client Registration Policies. If Dynamic Client Registration is necessary, ensure that policies are strictly configured to prevent anonymous client registration and require initial access tokens for all client registrations. Additionally, limit the `manage-client` role to only trusted administrators. Changes to Keycloak configuration may require a service restart or redeployment to take effect.

Official advisory · high-confidence parse· fetched 2 months ago·verify at source

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