The MONAI library up to version 1.6.0 contains a remote code execution vulnerability (CVE-2026-100840) in its bundle configuration engine. The vulnerability stems from the engine's unsafe resolution of _target_ values to arbitrary importable callables without restricting them via an allow list, combined with passing $ expressions to Python's eval() function. This allows an attacker to publish a malicious bundle with crafted configuration data that executes arbitrary code upon loading or running the bundle with monai.bundle.load() or monai.bundle.run(). The CVSS 3.1 base score is 7.8, indicating a high severity with high impact on confidentiality, integrity, and availability. The attack vector is local (AV:L), requiring user interaction (UI:R) but no privileges (PR:N).

Successful exploitation allows remote code execution on the victim's system when a malicious bundle is loaded or run. This can lead to full compromise of the affected system, including unauthorized access, data modification, and service disruption.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid loading or running bundles from untrusted sources. Monitor vendor channels for updates and apply patches promptly once released.