CVE-2026-107914 in Backdrop
Summary
by MITRE • 10/09/2026
Backdrop CMS 1.34 before 1.34.5 and 1.35 before 1.35.1 doesn't sufficiently protect configuration exports when delivering a compressed archive. This vulnerability is mitigated by the fact that an export must have been previously requested by someone with the "Synchronize, import, and export configuration" permission.
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Analysis
by VulDB Data Team • 10/09/2026
The identified security issue in Backdrop CMS versions prior to 1.34.5 and 1.35.1 centers on insufficient access controls during the delivery of compressed configuration archives. When a user requests a site-wide configuration export, the system packages these settings into an archive file for download. The vulnerability arises because this delivery mechanism does not adequately verify that the requestor possesses the necessary privileges to view or handle sensitive configuration data at the moment of transmission. This represents a classic case where authorization checks are performed during the initial request phase but fail to persist or re-validate when the actual resource is served, potentially allowing unauthorized users to retrieve critical system settings if they can trigger the export process through other means or exploit race conditions in permission evaluation.
From a technical perspective, this flaw aligns with CWE-284 Improper Access Control and specifically relates to CWE-732 Incorrect Permission Assignment for Critical Resource. The configuration files exported by Backdrop CMS often contain sensitive information such as database connection strings, API keys, site-wide settings, and potentially user role definitions. If an attacker can induce the system to generate and deliver this archive without proper verification of their current session privileges, they gain access to data that should be restricted to administrators or users with explicit synchronization permissions. The mitigation note indicates that a valid export request must originate from a user who holds the Synchronize, import, and export configuration permission, implying that the vulnerability likely stems from a failure to enforce this check strictly during the file delivery phase rather than just at the point of initiating the export action.
The operational impact of this vulnerability is significant for organizations relying on Backdrop CMS for their web infrastructure. Successful exploitation could lead to information disclosure, allowing attackers to map out the system architecture, identify weak points in authentication mechanisms via exposed configuration details, or prepare more targeted attacks against specific services defined in the exported settings. While the requirement that an export must have been previously requested by a privileged user limits the attack surface compared to unrestricted file downloads, it does not eliminate risk entirely. Attackers might exploit session hijacking, cross-site request forgery, or privilege escalation vulnerabilities to impersonate a legitimate administrator and trigger the export process, thereby bypassing the intended access controls through indirect means rather than direct exploitation of this specific flaw.
To mitigate this vulnerability, administrators should immediately upgrade Backdrop CMS to version 1.34.5 or later for the 1.34 branch, or version 1.35.1 and later for the 1.35 branch. These releases include patches that enforce stricter access control checks during the archive delivery phase, ensuring that only users with verified current privileges can download configuration exports. Additionally, organizations should review their permission assignments to ensure that the Synchronize, import, and export configuration role is granted strictly to trusted administrators. Implementing additional monitoring for unusual export activities or large file downloads from administrative endpoints can provide early warning of potential exploitation attempts. Regular security audits and adherence to principle of least privilege will further reduce the risk associated with sensitive data handling within the CMS environment.