CVE-2026-100840 MONAI through 1.6.0 Remote Code Execution via bundle configuration

High 8.5 Published 27 Sep 2026 Updated 28 Sep 2026

Attackers can execute arbitrary code by publishing malicious MONAI bundles that exploit unsafe configuration evaluation, requiring users to upgrade the library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2026-100840?

CVE-2026-100840 is a high-severity code injection vulnerability in Project-MONAI MONAI, published on 27 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

MONAI through 1.6.0 contains a remote code execution vulnerability in the bundle configuration engine that resolves _target_ values to arbitrary importable callables without an allow list and passes $ expressions to Python eval(). Attackers can publish a malicious bundle with crafted configuration containing arbitrary code that executes when a victim loads the bundle using monai.bundle.load() or monai.bundle.run().

Weakness: CWE-95

Which versions are affected by CVE-2026-100840?

1 open source package ship an affected version, including monai. It affects 1 product.

Package	Affected	Fixed in
`monai` PyPI	All versions	`1.6.1rc0`

Products include Project-Monai Monai.

How do I fix CVE-2026-100840?

Upgrade monai to 1.6.1rc0 or later.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2026-100840 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100840 exists.

Sources

Also known as GHSA-873f-pvrv-4x83, GHSA-8jxj-xq3g-hvm2, PYSEC-2026-4015.