CVE-2026-116897 in Redaxo
Summary
by MITRE • 10/27/2026
REDAXO core before 5.21.4 contains a missing authorization vulnerability in the structure/version and structure/history frontend preview modes, which do not check category or clang permissions for the previewed article. Any backend user, or one holding history[article_rollback], can set rex_version or rex_history_date with arbitrary article_id values to read unpublished working versions and historic or deleted content.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified in REDAXO core prior to version 5.21.4 represents a critical failure in access control mechanisms, specifically classified under CWE-862 as Missing Authorization. This flaw resides within the structure/version and structure/history frontend preview modes of the content management system. The fundamental technical issue is that these specific interface endpoints fail to validate whether the requesting user possesses the necessary permissions for the category or language (clang) associated with the article being accessed via a preview request. In secure application design, every access attempt must be verified against the current session's privileges and the resource's security attributes before granting entry. Here, the system accepts arbitrary inputs without performing this essential check, effectively bypassing the intended role-based access control model that protects sensitive content from unauthorized viewing or modification.
The operational impact of this vulnerability is severe for organizations relying on REDAXO to manage confidential or unpublished data. An attacker who has authenticated as any backend user, including those with minimal privileges such as editors, can exploit this flaw by manipulating the rex_version and rex_history_date parameters in HTTP requests. By supplying arbitrary article_id values alongside these parameters, an adversary can force the system to render previews of articles that are not yet published, have been deleted from the live site, or exist only in historical drafts. This capability allows for the exfiltration of sensitive information that was intended to remain internal during its development phase. Furthermore, users holding specific permissions like history[article_rollback] can leverage this flaw to access even more granular control over content states, potentially leading to further unauthorized modifications if combined with other vulnerabilities or misconfigurations.
This type of vulnerability aligns closely with the MITRE ATT&CK technique T1078, Valid Accounts, as it relies on legitimate authentication credentials but abuses their permissions through flawed logic rather than credential theft. It also reflects aspects of CWE-269, Improper Privilege Management, where the application fails to enforce appropriate separation between different levels of access. The ability to view unpublished content poses significant risks including intellectual property leakage, exposure of personal data in violation of regulations like GDPR or CCPA if such data is present in drafts, and reputational damage resulting from premature disclosure of marketing materials or strategic plans.
To mitigate this vulnerability, organizations must immediately upgrade the REDAXO core to version 5.21.4 or later, where these authorization checks have been implemented. Until an update can be applied, administrators should implement strict input validation on the server side for all preview endpoints, ensuring that any article_id provided in a request is cross-referenced against the user's assigned category and language permissions before rendering content. Additionally, implementing web application firewalls with rulesets capable of detecting parameter manipulation attempts may provide an additional layer of defense by blocking requests where rex_version or rex_history_date are set to values inconsistent with standard usage patterns for unauthenticated or low-privilege users. Regular security audits focusing on access control logic in preview and history modules should be conducted to prevent similar flaws from persisting in custom extensions or future updates.