REDHAT-BUG-2429869: Input Validation

Published Jan 15, 2026
·
Updated

Improper input validation vulnerability in Keycloak related to the handling of matrix parameters in URL paths. The issue occurs because Keycloak, via its JAX-RS routing layer, accepts RFC-compliant matrix parameters (e.g., ;param) in path segments, while common reverse proxy configurations may ignore or mishandle them when enforcing access restrictions. A remote attacker can craft requests such as /realms;abc/master/account to mask path segments and bypass proxy-level path filtering. Although authentication is still required, this may expose administrative or sensitive endpoints that operators believe are not externally reachable. Exploitation is network-based, requires no authentication, and depends on the reverse proxy configuration in front of Keycloak.

Affected Software

1 affected component
Red Hat Keycloak

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Compensating control

    Update the reverse proxy (fronting Keycloak) path filtering/access-restriction rules to properly handle RFC-compliant matrix parameters in URL path segments (e.g., segments containing ";param") so crafted paths like "/realms;abc/master/account" cannot mask path segments and bypass proxy-level filtering.

Event History

Jan 15, 2026
Data Sourced
via Red Hat·07:10 AM
DescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2429869?

The severity of REDHAT-BUG-2429869 is considered high due to potential exploitation via improper input validation.

2

How do I fix REDHAT-BUG-2429869?

To fix REDHAT-BUG-2429869, ensure you apply the latest security patch provided by Red Hat for Keycloak.

3

What impact does REDHAT-BUG-2429869 have on my system?

The impact of REDHAT-BUG-2429869 could allow an attacker to manipulate URL parameters and potentially bypass security mechanisms.

4

Which versions of Keycloak are affected by REDHAT-BUG-2429869?

REDHAT-BUG-2429869 affects all currently supported versions of Red Hat Keycloak that do not have the appropriate patch.

5

Is there a workaround for REDHAT-BUG-2429869?

A possible workaround for REDHAT-BUG-2429869 is to reconfigure the reverse proxy to correctly handle matrix parameters.

Contact

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