Is CVE-2026-100846 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-100846 being exploited in the wild.

How severe is CVE-2026-100846?

High severity, with a CVSS score of 7.6, published 27 September 2026.

Which products and versions are affected?

Project-MONAI MONAI before 1.5.2; monai (PyPI) ECOSYSTEM:introduced=0,fixed=1.5.2.

Is there a fix for CVE-2026-100846?

Yes. monai (PyPI): upgrade to 1.5.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-100846 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-100846?

Check whether you run Project-MONAI MONAI or monai (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-100846: MONAI unsafe deserialization in algo_from_pickle

CVE-2026-100846 · Severity: high · CVSS 7.6 · Published 2026-09-27

MONAI is a medical imaging AI library used for automated 3D segmentation analysis. The algo_from_pickle function loads algorithm objects from pickle files without validation, allowing an attacker to craft a malicious pickle file that executes arbitrary code when loaded. An application using this function to process untrusted pickle files could be compromised with full system access.

Technologies: Project-MONAI MONAI, monai (PyPI). Vendors: Project-MONAI, PyPI.

Quick answers

Is CVE-2026-100846 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-100846 being exploited in the wild.
How severe is CVE-2026-100846?: High severity, with a CVSS score of 7.6, published 27 September 2026.
Which products and versions are affected?: Project-MONAI MONAI before 1.5.2; monai (PyPI) ECOSYSTEM:introduced=0,fixed=1.5.2.
Is there a fix for CVE-2026-100846?: Yes. monai (PyPI): upgrade to 1.5.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-100846 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-100846?: Check whether you run Project-MONAI MONAI or monai (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

monai (PyPI): upgrade to 1.5.2 or later
```
pip install "monai>=1.5.2"
```

Technical details

The algo_from_pickle function in monai/auto3dseg/utils.py deserializes pickle data via pickle.loads() without validating input, enabling arbitrary code execution through __reduce__ gadgets. An attacker must supply a malicious .pkl file and the application must invoke algo_from_pickle on it; the exploit runs in the application's security context. A fix is available in MONAI 1.5.2.

Affected products

Project-MONAI MONAI before 1.5.2

Identifiers

CVE-2026-100846
GHSA-89gg-p5r5-q6r4
PYSEC-2026-4021

Timeline

2026-09-27: disclosed
2026-04-03: patched: Version 1.5.2 released

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.