Which versions of pynetdicom are affected by CVE-2026-56445?

The pynetdicom library's qrscp storage application contains a critical arbitrary file-write vulnerability that allows unauthenticated remote attackers to write files to any path on the host system.

How to fix or mitigate CVE-2026-56445?

Within 24 hours: Inventory all systems running pynetdicom and identify internet-facing or untrusted-network deployments. Within 7 days: Restrict DICOM C-STORE network access via firewall rules to known-trusted sender IPs only; disable qrscp if operationally nonessential. Within 30 days: Monitor pynetdicom project releases for patch availability; plan upgrade timeline; conduct forensic review of DICOM logs and file system for suspicious writes.

pynetdicom CVE-2026-56445

Q: What is the CVSS score of CVE-2026-56445?

CVE-2026-56445 has a CVSS 4.0 base score of 8.8 (High). CVSS vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.4%.

EUVD-2026-39562 HIGH

Path Traversal (CWE-22)

2026-06-25 icscert

GHSA-f3pc-ww42-cwqp

Path Traversal Pynetdicom Library

8.8

CVSS 4.0 · Vendor: icscert

Severity by source

Vendor (icscert) PRIMARY

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

9.1 CRITICAL

Remote unauthenticated C-STORE to a listening SCP gives AV:N/AC:L/PR:N/UI:N; arbitrary file write yields I:H and A:H with no direct disclosure (C:N).

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (icscert).

CVSS VectorVendor: icscert

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Jun 25, 2026 - 21:16 vuln.today

DescriptionCVE.org

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.

AnalysisAI

Arbitrary file write in the pynetdicom library's qrscp storage SCP application allows a remote, unauthenticated attacker to plant files at attacker-chosen paths on the receiving host. The qrscp C-STORE handler trusts a value taken from an incoming DICOM dataset and passes it into os.path.join() without sanitization, so a crafted instance identifier containing path-traversal sequences escapes the intended storage directory. No public exploit has been identified at time of analysis, but the CVSS 4.0 base score of 8.8 and unauthenticated network reachability make this a high-priority issue for any exposed DICOM endpoint.

Technical ContextAI

pynetdicom is a pure-Python implementation of the DICOM upper-layer networking protocol, widely used to build DICOM Storage SCP/SCU services and PACS-adjacent tooling in medical imaging. Its bundled qrscp Query/Retrieve application acts as a Storage SCP: when it receives a C-STORE request, it persists the incoming SOP Instance to disk using a filename derived from the dataset. The root cause is CWE-22 (Improper Limitation of a Pathname to a Restricted Directory / Path Traversal): a specific attacker-controlled instance attribute (e.g. the SOP Instance UID) is concatenated into a destination path via os.path.join() with no validation. Because os.path.join() resolves an absolute or '../'-laden second argument relative to (or in place of) the base directory, the attacker controls where the file lands. The affected component per CPE is cpe:2.3:a:pydicom:pynetdicom_library, reported by ICS-CERT under advisory ICSMA-26-176-01, reflecting its use in medical/OT environments.

RemediationAI

Upstream fix status is not independently confirmed from the provided data - no exact patched version is given in the references - so monitor the pydicom/pynetdicom repository (https://github.com/pydicom/pynetdicom) and the CISA advisory ICSMA-26-176-01 (https://www.cisa.gov/news-events/ics-medical-advisories/icsma-26-176-01) for the official fixed release and upgrade to it once published. As compensating controls until then: restrict which Application Entity titles and source IPs may connect to the qrscp SCP via network ACLs and DICOM AE allow-listing so only trusted modalities can issue C-STORE (trade-off: must maintain the modality inventory); place the storage service on a segmented imaging VLAN with no direct internet exposure; and if you maintain the deployment, run qrscp under a low-privilege account with a dedicated, restricted storage directory and a restrictive umask so an escaped write cannot reach sensitive system paths (trade-off: does not stop the traversal, only limits blast radius). If feasible, validate or hash incoming SOP Instance UIDs before using them as filenames rather than passing raw dataset values to os.path.join().