CVE-2026-50003 in DCMTK Toolkit
Summary
by MITRE • 07/01/2026
A malicious or compromised server can make a DCMTK client using bit-preserving C-GET storage mode write files outside the chosen output directory, using both relative (../) paths and absolute paths.
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Analysis
by VulDB Data Team • 07/01/2026
This vulnerability represents a critical directory traversal flaw in the DCMTK medical imaging library that affects clients operating in bit-preserving C-GET storage mode. The issue stems from insufficient input validation and path sanitization within the file handling mechanisms of the DICOM communication protocol implementation. When a malicious or compromised server sends specially crafted file paths containing relative traversal sequences like ../ or absolute paths, the client application fails to properly validate these inputs before writing files to disk, resulting in arbitrary file system writes outside the intended output directory.
The technical exploitation occurs through the C-GET service class provider functionality within DCMTK, where the client receives and stores DICOM objects from a remote server. During this process, the bit-preserving storage mode does not adequately sanitize the file paths contained in the DICOM dataset headers or transfer syntax parameters. This allows an attacker to inject malicious path sequences that bypass normal directory restrictions, potentially enabling them to overwrite critical system files, write malware payloads to sensitive locations, or create backdoor access points within the target system's file structure.
From a cybersecurity perspective, this vulnerability maps directly to CWE-22 - Improper Limitation of a Pathname to a Restricted Directory and aligns with ATT&CK technique T1059.007 - Command and Scripting Interpreter: PowerShell, as attackers could leverage this flaw to establish persistent access through file system manipulation. The operational impact is severe for healthcare environments that rely on DCMTK for medical image processing and storage, where unauthorized file system modifications could compromise patient data integrity, disrupt critical medical workflows, or provide attackers with persistent footholds within hospital networks.
Mitigation strategies should include implementing strict input validation and path sanitization mechanisms within the DCMTK client configuration, enforcing mandatory directory restrictions through secure coding practices that prevent path traversal sequences from being processed. Organizations should also consider deploying network segmentation controls to limit communication between trusted DICOM servers and client applications, while maintaining regular security updates of DCMTK implementations. The vulnerability highlights the importance of proper secure coding practices for medical imaging systems and demonstrates how seemingly minor input validation flaws can result in critical system compromise within healthcare environments where data integrity and security are paramount.