View CSAF Summary Successful exploitation of this vulnerability could allow an unauthenticated attacker to write to arbitrary file paths. The following versions of pydicom pynetdicom Library are affected: pynetdicom >=v1.0.0|<v3.0.4 CVSS Vendor Equipment Vulnerabilities v3 9.1 pydicom pydicom pynetdicom Library Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') Background Critical Infrastructure Sectors: Healthcare and Public Health Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2026-56445 The qrscp application's C-STORE handler uses a specific instance from attacker-supplied DICOM datasets directly in os.path.join() without sanitization, allowing file writes to arbitrary paths. View CVE Details Affected Products pydicom pynetdicom Library Vendor: pydicom Product Version: pydicom pynetdicom: >=v1.0.0|<v3.0.4 Product Status: known_affected Remediations Vendor fix The maintainer of pynetdicom has not responded to requests to work with CISA to mitigate this vulnerability. For update information, refer to the github page https://github.com/pydicom/pynetdicom. https://github.com/pydicom/pynetdicom Relevant CWE: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') Metrics CVSS Version Base Score Base Severity Vector String 3.1 9.1 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H 4.0 8.8 HIGH CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N Acknowledgments Simon Weber and Volker Schönefeld of Machine Spirits UG reported this vulnerability to CISA Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. Revision History Initial Release Date: 2026-06-25 Date Revision Summary 2026-06-25 1 Initial Publication Legal Notice and Terms of Use