# CVE-2026-21851: PYSEC-2026-1678 - MONAI has Path Traversal (Zip Slip) in NGC Private Bundle Download

Source: https://junglewise.ai/threats/cve-2026-21851-monai-has-path-traversal-zip-slip-in-ngc-private-bundle-download  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07  
License: CC BY 4.0 with a link back

CVE-2026-21851 · Severity: low · CVSS 3.1 · Published 2026-07-07

MONAI has Path Traversal (Zip Slip) in NGC Private Bundle Download

Technologies: [monai (PyPI)](https://junglewise.ai/threats/technologies/monai). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-21851 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-21851 being exploited in the wild.

**How severe is CVE-2026-21851?** Low severity, with a CVSS score of 3.1, published 7 July 2026.

**Which products and versions are affected?** monai (PyPI) ECOSYSTEM:introduced=0,fixed=1.5.2.

**Is there a fix for CVE-2026-21851?** 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.

**Am I affected by CVE-2026-21851?** Check whether you run 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

  ```sh
  pip install "monai>=1.5.2"
  ```


## Affected products

- monai (PyPI) ECOSYSTEM:introduced=0,fixed=1.5.2

## Identifiers

- CVE-2026-21851
- GHSA-9rg3-9pvr-6p27
- PYSEC-2026-1678

## 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 unsafe deserialization in algo_from_pickle](https://junglewise.ai/threats/cve-2026-100846-monai-before-1-5-2-contains-a-deserialization-of-untrusted-data)
- [MONAI unsafe deserialization in NumpyReader](https://junglewise.ai/threats/cve-2026-100845-monai-before-1-6-0-contains-an-unsafe-deserialization)
- [MONAI OS command injection in nnUNetV2Runner](https://junglewise.ai/threats/cve-2026-100844-monai-before-1-6-0-is-vulnerable-to-os-command-injection-in-the)
- [MONAI remote code execution in algo_from_pickle](https://junglewise.ai/threats/cve-2026-100843-monai-versions-before-1-6-0-contain-a-remote-code-execution)