CVE-2026-102249 in REBUILD
Summary
by MITRE • 09/29/2026
A security flaw has been discovered in REBUILD up to 4.4.11. This vulnerability affects unknown code of the file /commons/file-editor-save. The manipulation of the argument url/fileKey results in missing authorization. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability identified within REBUILD versions up to 4.4.11 represents a critical failure in access control mechanisms, specifically categorized under CWE-862 Missing Authorization. This flaw resides within the codebase associated with the file path /commons/file-editor-save, indicating that the issue is embedded deep within the application's core functionality for handling file operations. The root cause of this vulnerability lies in the improper validation of input arguments, particularly the url and fileKey parameters passed to the endpoint responsible for saving or modifying files. Because the system fails to verify whether the authenticated user has sufficient privileges to perform actions on the specific resource identified by these keys, an attacker can bypass intended security restrictions entirely. This type of flaw is a classic example of insecure direct object references where the application relies solely on client-supplied identifiers without enforcing server-side access checks against the underlying data model or user permissions.
The operational impact of this vulnerability is severe due to its remote exploitability and the nature of the affected component. Since the file-editor-save endpoint likely handles sensitive document management tasks, a successful exploitation could allow an unauthenticated attacker to upload malicious files, overwrite existing critical documents, or potentially achieve arbitrary code execution if the saved content includes executable scripts that are subsequently processed by the server. The fact that public exploits have been released significantly elevates the risk profile, as automated scanning tools and threat actors can readily leverage these proof-of-concept codes to identify vulnerable instances across the internet without requiring specialized knowledge of the internal architecture. This widespread availability means that systems running affected versions are under constant active surveillance by malicious entities seeking to compromise data integrity or gain a foothold within the network infrastructure hosting the application.
From an offensive security perspective, this vulnerability aligns with several techniques outlined in the MITRE ATT&CK framework. The initial access and privilege escalation aspects relate to T1078 Valid Accounts if authentication is bypassed through other means, but more directly it reflects T1546 Trust Relationship Abuse or general unauthorized API manipulation where the attacker exploits a lack of proper authorization checks on an application interface. Furthermore, depending on how the file editor processes the saved content, subsequent actions could map to T1059 Command and Scripting Interpreter if script injection is possible, allowing for further lateral movement within the target environment. The absence of effective input validation combined with missing access control creates a high-severity entry point that can serve as the initial vector for more complex multi-stage attacks aimed at data exfiltration or system compromise.
Mitigation strategies must prioritize immediate remediation given the public availability of exploits and the vendor's lack of response to disclosure attempts. The most effective solution is to upgrade REBUILD to a version later than 4.4.11 where this authorization logic has presumably been corrected by the developers, although users should verify patch notes for specific fixes related to file handling security. In cases where upgrading is not immediately feasible due to compatibility constraints or operational downtime requirements, temporary compensating controls are essential. These include implementing a Web Application Firewall rule set that monitors and restricts requests to the /commons/file-editor-save endpoint based on strict parameter validation patterns and known exploit signatures associated with this vulnerability. Additionally, enforcing rigorous authentication checks at the application layer by ensuring that every request to file management endpoints verifies both user session validity and explicit permission rights against the requested resource identifier is critical. Regular security audits focusing on access control logic across all API endpoints will help identify similar misconfigurations before they can be exploited in production environments.