# CVE-2026-100842: MONAI eval injection in _get_fake_spatial_shape

Source: https://junglewise.ai/threats/cve-2026-100842-monai-through-1-6-0-contains-an-eval-injection-vulnerability-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-27. Updated: 2026-09-27  
License: CC BY 4.0 with a link back

CVE-2026-100842 · Severity: high · CVSS 7 · Published 2026-09-27

MONAI is a medical imaging AI framework that processes computational models and bundles. An attacker who can control a bundle's metadata configuration can inject Python code that bypasses security filters and executes arbitrary commands. This could allow an attacker to steal data, modify models, or compromise systems that use MONAI to process medical imaging bundles.

Technologies: [Project-MONAI MONAI](https://junglewise.ai/threats/technologies/project-monai-monai), [monai (PyPI)](https://junglewise.ai/threats/technologies/monai). Vendors: [Project-MONAI](https://junglewise.ai/threats/vendors/project-monai), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-100842 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100842 being exploited in the wild.

**How severe is CVE-2026-100842?** High severity, with a CVSS score of 7, published 27 September 2026.

**Which products and versions are affected?** Project-MONAI MONAI through 1.6.0; monai (PyPI) ECOSYSTEM:introduced=0,fixed=1.6.1rc0.

**Is there a fix for CVE-2026-100842?** Yes. monai (PyPI): upgrade to 1.6.1rc0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-100842 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-100842?** 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 1.6.1rc0 or later

  ```sh
  pip install "monai>=1.6.1rc0"
  ```


## Technical details

The vulnerability is an eval injection (CWE-95) in _get_fake_spatial_shape() within monai/bundle/scripts.py. The function validates shape expressions by checking for ast.Name nodes and rejecting names outside a whitelist (p, n), but expressions using only object introspection chains like "(1).__class__.__bases__[0].__subclasses__()" bypass this filter because they contain no ast.Name nodes. An attacker with the ability to influence bundle metadata (reachable through the verify_net_in_out CLI flow) can supply such expressions to achieve code execution.

## Affected products

- Project-MONAI MONAI through 1.6.0

## Identifiers

- CVE-2026-100842
- GHSA-h89g-r5pc-wxfm
- PYSEC-2026-4017

## Timeline

- 2026-09-27: disclosed

## References

- [https://github.com/Project-MONAI/MONAI/security/advisories/GHSA-h89g-r5pc-wxfm](https://github.com/Project-MONAI/MONAI/security/advisories/GHSA-h89g-r5pc-wxfm)
- [https://www.vulncheck.com/advisories/monai-through-1.6.0-get-fake-spatial-shape-eval-sandbox-bypass-via-attribute-chains](https://www.vulncheck.com/advisories/monai-through-1.6.0-get-fake-spatial-shape-eval-sandbox-bypass-via-attribute-chains)

## Related threats

- [MONAI MONAILabel server crash and inference corruption via crafted DICOM](https://junglewise.ai/threats/cve-2026-48705-monailabel-server-crash-and-silent-inference-corruption-via)
- [MONAI Auto3DSeg remote code execution via algo_from_json](https://junglewise.ai/threats/cve-2026-119578-monai-from-1-6-0-before-1-6-1-contains-a-remote-code-execution)
- [MONAI check_hash insufficient integrity verification](https://junglewise.ai/threats/cve-2026-118684-monai-before-1-6-1-contains-an-insufficient-integrity)
- [MONAI ConfigWorkflow remote code execution in logging.conf](https://junglewise.ai/threats/cve-2026-118683-monai-from-1-2-0-before-1-6-1-contains-a-remote-code-execution)
- [MONAI nnUNetV2Runner insecure deserialization in postprocessing](https://junglewise.ai/threats/cve-2026-109361-monai-1-2-0-before-1-6-1-contains-an-insecure-deserialization)