Grassroots DICOM (GDCM)

1. EXECUTIVE SUMMARY

CVSS v4 6.8
ATTENTION: Low attack complexity
Vendor: Grassroots
Equipment: DICOM (GDCM)
Vulnerability: Out-of-bounds Write

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to craft a malicious DICOM file and, if opened, could crash the application resulting in a denial-of-service condition.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following open source products and specified components are affected:

Grassroots DICOM (GDCM): Versions 3.0.24 and prior
SimpleITK: Versions 2.5.2 and prior
medInria: Versions 4.0 and prior

3.2 VULNERABILITY OVERVIEW

3.2.1 OUT-OF-BOUNDS WRITE CWE-787

An out-of-bounds write vulnerability exists in the Grassroots DICOM library (GDCM). The issue is triggered during parsing of a malformed DICOM file containing encapsulated PixelData fragments (compressed image data stored as multiple fragments). This vulnerability leads to a segmentation fault caused by an out-of-bounds memory access due to unsigned integer underflow in buffer indexing. It is exploitable via file input, simply opening a crafted malicious DICOM file is sufficient to trigger the crash, resulting in a denial-of-service condition.

CVE-2025-11266 has been assigned to this vulnerability. A CVSS v3.1 base score of 6.6 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H).

A CVSS v4 score has also been calculated for CVE-2025-11266. A base score of 6.8 has been calculated; the CVSS vector string is (AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N).

3.3 BACKGROUND

CRITICAL INFRASTRUCTURE SECTORS: Healthcare and Public Health
COUNTRIES/AREAS DEPLOYED: Worldwide
COMPANY HEADQUARTERS LOCATION: United States

3.4 RESEARCHER

Morgen Malinoski reported this vulnerability to CISA.

4. MITIGATIONS

The maintainer of the software recommends users update Grassroots DICOM (GDCM) to v3.2.2 or later from the main GitHub repository.

SimpleITK and medInria have both released fixes for the vulnerability.

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability, such as:

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.

CISA also recommends users take the following measures to protect themselves from social engineering attacks:

Do not click web links or open attachments in unsolicited email messages.
Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams.
Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks.

No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability is not exploitable remotely.

5. UPDATE HISTORY

December 11, 2025: Initial Publication