Vulnerability

Grassroots DICOM library crashes on crafted PixelData fragments, affecting SimpleITK and medInria

MedDevice Cyber Staff · Dec 11 · 3 min read · Via CISA ICSMA-25-345-01

CISA published advisory ICSMA-25-345-01 on December 11, 2025, for an out-of-bounds write (CWE-787) in the open source Grassroots DICOM library (GDCM). CVE-2025-11266 has a CVSS v3.1 base score of 6.6. Morgen Malinoski reported it.

The bug triggers while GDCM parses a malformed DICOM file with encapsulated PixelData fragments, the compressed image data stored as multiple pieces. An unsigned integer underflow in buffer indexing produces an out-of-bounds memory access and a segmentation fault. Opening the crafted file is enough.

CISA rates the outcome as denial of service: the application crashes. The vector is local with user interaction, and it also scores low confidentiality and integrity impact.

Because GDCM is a library, the affected list reaches past it. CISA names GDCM 3.0.24 and earlier, SimpleITK 2.5.2 and earlier, and medInria 4.0 and earlier. The maintainer recommends GDCM 3.2.2 or later from the main GitHub repository, and SimpleITK and medInria have both shipped fixes.

Any imaging product that embeds GDCM inherits this bug until it rebuilds against 3.2.2. Device makers should check their SBOMs for the library rather than wait for an advisory under their own name.

Are you a representative of SimpleITK or medInria? Submit an official response →

Remediation Desk

For ProvidersOperators, hospitals, and clinical engineering

Update GDCM to 3.2.2 or later, and update SimpleITK and medInria to their fixed releases. Manufacturers that embed GDCM in imaging software should rebuild against 3.2.2 and ship the update. Until then, treat DICOM files from outside sources as untrusted.

Update GDCM. Move to GDCM 3.2.2 or later from the maintainer's GitHub releases.
Update downstream tools. Install the fixed SimpleITK and medInria releases.
Search SBOMs for GDCM. Find every product and internal tool that links GDCM 3.0.24 or earlier and schedule a rebuild.

For Device ManufacturersAm I affected, and how to fix the class

Am I affected?

This class applies to devices with the signals and properties below. Check them against your product to gauge exposure. The named product rows list what the sources state about the affected product.

Required

DICOM or image parsing

Contributing

Off-the-shelf software File import

Grassroots DICOM (GDCM)

DICOM or image parsing Off-the-shelf software

Fix the class in your product

A crafted file drives the parser out of bounds. As the maker, validate every length and offset against the real buffer before you copy, decode in a sandboxed least-privilege process, and fuzz the path continuously so the next bug is yours to find.

Bound every copy. Check declared sizes against allocated buffers before memcpy; prefer memory-safe parsers for new work.
Sandbox the decoder. Run it least-privilege and isolated so a crash or exploit is contained, not privileged.
Fuzz as a release gate. Run malformed-input fuzzing on every file-format parser before shipping.

Mapped EMB3D mitigations

Questions & Answers

What is CVE-2025-11266 in Grassroots DICOM (GDCM)?

CVE-2025-11266 is an out-of-bounds write (CWE-787, CVSS v3.1 6.6) in GDCM 3.0.24 and earlier, triggered by a malformed DICOM file with encapsulated PixelData fragments. Opening the file crashes the application. CISA disclosed it in advisory ICSMA-25-345-01 on December 11, 2025.

Are SimpleITK and medInria affected by the GDCM vulnerability?

Yes. CISA advisory ICSMA-25-345-01 lists SimpleITK 2.5.2 and earlier and medInria 4.0 and earlier as affected by CVE-2025-11266 in GDCM, and both projects have released fixes. GDCM itself is fixed in 3.2.2.

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