CVE-2026-63619 in Kylin
Summary
by MITRE • 10/16/2026
Missing Authorization vulnerability in Apache Kylin. A backend metadata dump API misses the enough authorization and the path-confinement. Impact most to the kylin services that are directly exposed to public network, which is not common. In-house kylin deployments are mostly not impacted.
This issue affects Apache Kylin: from 4 through 5.0.4.
Users are recommended to upgrade to version 5.0.5, which fixes the issue.
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Analysis
by VulDB Data Team • 10/16/2026
The vulnerability identified in Apache Kylin represents a critical failure in access control mechanisms within the backend metadata dump application programming interface. This flaw stems from insufficient authorization checks and a lack of proper path confinement, allowing authenticated users to potentially access sensitive system information beyond their intended scope. In the context of enterprise data warehousing solutions like Apache Kylin, which manages large-scale analytical processing, such exposure can lead to significant security compromises if not properly mitigated through network segmentation or strict authentication policies.
The technical nature of this vulnerability involves an API endpoint designed for dumping backend metadata that does not adequately verify whether the requesting user has permission to access specific resources. Furthermore, the absence of path confinement means that attackers may traverse directories or access internal structures that are meant to be isolated from standard operational workflows. This type of flaw is characteristic of improper privilege management where the application fails to enforce strict boundaries between different levels of system authority and data accessibility.
The impact of this vulnerability is heavily dependent on the deployment architecture of the Apache Kylin instance. For services directly exposed to public networks, the risk is substantial as external actors could exploit the missing authorization to extract sensitive metadata, potentially revealing table structures, query logs, or other configuration details that aid in further attacks. However, for most in-house deployments where Kylin operates behind firewalls and internal network boundaries, the immediate threat level is considerably lower due to restricted access vectors. Despite this reduced exposure for internal setups, the vulnerability remains a serious concern because it violates fundamental security principles regarding data confidentiality and integrity.
This issue affects Apache Kylin versions ranging from 4 through 5.0.4 inclusive. Organizations running these older versions are advised that their systems may be susceptible to exploitation if exposed to untrusted networks or if internal users have elevated privileges without proper oversight. The lack of robust access controls in the metadata dump functionality creates a potential attack surface for information disclosure, which can serve as a precursor to more severe compromises such as data manipulation or service disruption.
To mitigate this risk, it is strongly recommended that all affected organizations upgrade Apache Kylin to version 5.0.5 or later. This release includes patches that address the authorization gaps and enforce stricter path confinement within the backend metadata API. Additionally, administrators should review their network security policies to ensure that administrative interfaces are not unnecessarily exposed to public networks. Implementing multi-factor authentication for administrative accounts and regularly auditing access logs can further reduce the likelihood of successful exploitation even if vulnerabilities persist in other components.
From a classification perspective, this vulnerability aligns with CWE-269 Improper Privilege Management, as it involves an actor obtaining privileges that they should not possess due to flawed authorization logic. It also relates to CWE-732 Incorrect Permission Assignment for Critical Resource, reflecting the failure to restrict access to sensitive metadata endpoints appropriately. In terms of offensive security frameworks such as MITRE ATT&CK, this flaw facilitates techniques associated with Discovery and Collection phases, where adversaries gather information about the target environment to plan subsequent actions. By addressing these authorization deficiencies through software updates and network hardening, organizations can significantly reduce their risk profile regarding unauthorized data access in Apache Kylin deployments.