Katello RegistryProxiesController Auth Bypass Enables User Enumeration
CVE-2026-56098 Published on October 1, 2026
Rubygem-katello: improper authorization logic allows resource enumeration
A flaw was found in rubygem-katello. The RegistryProxiesController in Katello contains an authorization bypass vulnerability due to an execution fall-through in the registry_authorize filter. While the application identifies unauthorized requests and triggers an error response via the unauthorized method, it fails to halt the execution of the current code path (missing return statement). This failure in the control flow allows the application to proceed into subsequent business logic and database validation filters. Consequently, the application reveals its internal state through differential responses, allowing an unprivileged attacker to enumerate valid Users, Organizations, and Products across the entire instance.
Vulnerability Analysis
CVE-2026-56098 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public. 105 days later.
Weakness Type
What is a Side Channel Attack Vulnerability?
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not. Discrepancies can take many forms, and variations may be detectable in timing, control flow, communications such as replies or requests, or general behavior. These discrepancies can reveal information about the product's operation or internal state to an unauthorized actor. In some cases, discrepancies can be used by attackers to form a side channel.
CVE-2026-56098 has been classified to as a Side Channel Attack vulnerability or weakness.
Products Associated with CVE-2026-56098
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Affected Versions
Red Hat Satellite 6.19 for RHEL 9:- Version 0:4.20.0.11-1.el9sat and below * is unaffected.