CVE-2026-125637
Description
A flaw was found in the Konflux UI proxy. Hostname values defined in the KonfluxUI custom resource are inserted directly into proxy configuration files without adequate validation or sanitization. An authenticated user with permissions to modify the custom resource can inject malicious configuration directives to bypass authentication and authorization controls, potentially exposing internal backend services. In addition, providing malformed input can cause the configuration generator to fail, resulting in a denial of service (DoS) by preventing the proxy from starting.
Statement
Red Hat Product Security rates this vulnerability as Critical because successful exploitation completely circumvents the proxy's authentication and impersonation enforcement, granting unauthenticated access to internal backend services and the Kubernetes API. While triggering the vulnerability requires administrative privileges to modify the KonfluxUI custom resource or manage GitOps manifests, the resulting compromise undermines the primary security boundary the proxy was designed to establish.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Injected code can access resources that the attacker is directly prevented from accessing.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. As a result, code injection can often result in the execution of arbitrary code. Code injection attacks can also lead to loss of data integrity in nearly all cases, since the control-plane data injected is always incidental to data recall or writing.
Non-Repudiation
Technical Impact: Hide Activities
Often the actions performed by injected control code are unlogged.
Acknowledgements
Red Hat would like to thank abhi04anon - (GitHub) for reporting this issue.
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