OS Command Injection in MONAI (CVE-2026-100844)
Summary
OS command injection in MONAI (CVE-2026-100844). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
Comment from JPCERT/CC
We are submitting the report again as we have yet to receive
any responses from you after submitting it on February 5 and March 11.
It would be greatly appreciated if you could send us a message
after confirming it so that we can follow up the case by email.
Summary
MONAI vulnerable to OS command injection.
Details
This library concatenates user-controlled values (YAML's
"dataset_name_or_id" or part of "CLI/kwargs")
without quoting or validation. Since this string is passed to subprocess
with shell=True,
shell metacharacters (e.g., Windows: & / Linux: ;) are interpreted.
As a result, arbitrary commands can be concatenated and executed.
Therefore, the reporter identifies this as CWE-78 (OS Command Injection).
The victim needs to load a crafted YAML file in the code that launches
training/validation jobs
based on the configuration (YAML/arguments). There are no other constraints.
PoC
Verified on Windows.
Load a modified YAML file with crafted "dataset_name_or_id" as follows.
Add command separator characters (such as & or ;) and insert arbitrary
commands.
dataset_name_or_id: '4 & echo "This is exploited" >
"C:\Users\shima\OneDrive\Desktop\tmp\test.txt" & rem'
dataroot: C:/Users/shima/OneDrive/Desktop/tmp/data
datalist: C:/Users/shima/OneDrive/Desktop/tmp/lists/task4.json
work_dir: C:/Users/shima/OneDrive/Desktop/tmp/work
nnunet_raw: C:/Users/shima/OneDrive/Desktop/tmp/nnUNet_raw
nnunet_preprocessed: C:/Users/shima/OneDrive/Desktop/tm…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-100844 has been found in MONAI.
Successful exploitation can lead to full system takeover. CVSS score: 8.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "MONAI CVE-2026-100844" on the vendor's site.
CVE-2026-100844 (MONAI) — CWE-78 / CVSS v3 8.4
Attack vector: local / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
OS command injection (CWE-78) exists in MONAI.
Check the vendor advisory for the affected versions of MONAI.
Severity: High (CVSS 8.4/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'MONAI' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'MONAI' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
MONAIを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory vulncheck.com
- package github.com
- web github.com
- web nvd.nist.gov
- web github.com
- web github.com
- web github.com