CVE-2026-54005 in Kirby
Summary
by MITRE • 07/09/2026
Kirby is an open-source content management system. Prior to 4.9.4 and 5.4.4, Kirby sites where a role has the pages.access permission disabled allowed authenticated users who know or guess page IDs or UUIDs to retrieve page information, including full content and metadata, for arbitrary published pages through the /api/site/find route without authorization to access those pages. This issue is fixed in versions 4.9.4 and 5.4.4.
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Analysis
by VulDB Data Team • 07/09/2026
This vulnerability affects Kirby CMS installations prior to versions 4.9.4 and 5.4.4, representing a critical authorization bypass flaw that undermines the system's access control mechanisms. The issue stems from insufficient validation within the /api/site/find endpoint which allows authenticated users to retrieve page information regardless of their role permissions. When a user possesses knowledge of specific page IDs or UUIDs, they can exploit this vulnerability to access content that should otherwise be restricted based on their assigned permissions.
The technical flaw manifests in the API's handling of page retrieval requests where the system fails to properly verify whether the authenticated user has legitimate authorization to access the requested page content. This represents a classic case of insufficient authorization checks, which maps directly to CWE-862 - "Insufficient Authorization" and aligns with ATT&CK technique T1078.101 for Valid Accounts and T1566.002 for Phishing. The vulnerability allows attackers to enumerate published content by simply knowing or guessing page identifiers, bypassing the normal permission checking mechanisms that should prevent unauthorized access.
The operational impact of this vulnerability is severe as it enables arbitrary information disclosure across published pages within the CMS. An attacker with basic knowledge of page IDs or through systematic enumeration can access full page content including metadata, which may contain sensitive information, personal data, or proprietary business content. This represents a significant risk to data confidentiality and could lead to information leakage that violates privacy regulations and exposes organizations to potential legal consequences.
The fix implemented in versions 4.9.4 and 5.4.4 addresses the core authorization bypass by strengthening the permission validation logic within the /api/site/find route. This remediation ensures that all page access requests undergo proper authorization checks regardless of whether the user knows or guesses page identifiers. Organizations should immediately upgrade to these patched versions to mitigate the risk, while also implementing additional monitoring for unauthorized API access patterns and reviewing user permissions to ensure least privilege principles are maintained. Security teams should also consider implementing network-level controls to restrict access to sensitive API endpoints and establish proper logging mechanisms to detect potential exploitation attempts.
This vulnerability demonstrates the critical importance of proper authorization validation in web applications and highlights how seemingly minor permission gaps can result in significant information disclosure risks. The issue serves as a reminder that API endpoints must always validate user permissions against requested resources, regardless of whether authentication is successful or whether the user possesses knowledge of specific identifiers. Organizations relying on open-source CMS platforms should maintain regular update schedules and conduct security assessments to identify similar authorization bypass vulnerabilities in their systems.