CVE-2026-42145 in Coolify
Summary
by MITRE • 07/07/2026
Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to 4.0.0-beta.474, the file upload endpoint (app/Http/Controllers/UploadController.php) for database backup restore uploads did not enforce file type or size validation, allowing an authenticated user to upload unexpected or oversized files that could affect service availability. This issue is fixed in version 4.0.0-beta.474.
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Analysis
by VulDB Data Team • 07/07/2026
The vulnerability identified in Coolify versions prior to 4.0.0-beta.474 represents a critical security flaw in the file upload validation mechanism within the database backup restore functionality. This weakness exists specifically within the UploadController.php file located at app/Http/Controllers/UploadController.php, where the application fails to implement proper file type and size restrictions during the upload process. The absence of these validations creates an avenue for authenticated attackers to exploit the system by uploading malicious or oversized files that could potentially disrupt service availability and compromise system integrity.
The technical implementation flaw stems from inadequate input validation practices within the web application's file handling logic. When users authenticate and attempt to restore database backups through the designated upload endpoint, the system does not perform essential checks to verify that uploaded files conform to expected formats or size limitations. This vulnerability aligns with CWE-434 which specifically addresses "Unrestricted Upload of File with Dangerous Type" and represents a classic example of insecure file upload handling that enables attackers to potentially execute arbitrary code or consume excessive system resources through malicious file uploads.
From an operational perspective, this vulnerability presents significant risks to the availability and stability of Coolify deployments. An authenticated user could leverage this weakness to upload oversized files that consume excessive storage space or memory resources, leading to denial of service conditions for legitimate users. The impact extends beyond simple resource exhaustion as attackers might also attempt to upload malicious files designed to exploit other system components or establish persistence within the environment. This weakness particularly affects systems where Coolify manages critical database operations and backup restoration processes, making it a serious concern for organizations relying on automated infrastructure management.
The mitigation strategy for this vulnerability involves upgrading to version 4.0.0-beta.474 or later, which implements proper file type and size validation controls within the UploadController.php. Organizations should also consider implementing additional security measures such as restricting upload permissions to only necessary administrative users, implementing strict file extension filtering, setting reasonable size limits, and deploying content validation mechanisms. This fix aligns with ATT&CK technique T1203 which focuses on "Exploitation for Client Execution" and represents a fundamental security improvement that addresses the principle of least privilege in file handling operations. The remediation process should also include regular security testing of upload endpoints to ensure that similar vulnerabilities do not emerge in other parts of the application architecture, particularly in systems where file processing capabilities are exposed through web interfaces.