CVE-2026-21851
Unknown Unknown - Not Provided
Path Traversal in MONAI _download_from_ngc_private() Function

Publication date: 2026-01-07

Last updated on: 2026-02-02

Assigner: GitHub, Inc.

Description
MONAI (Medical Open Network for AI) is an AI toolkit for health care imaging. In versions up to and including 1.5.1, a Path Traversal (Zip Slip) vulnerability exists in MONAI's `_download_from_ngc_private()` function. The function uses `zipfile.ZipFile.extractall()` without path validation, while other similar download functions in the same codebase properly use the existing `safe_extract_member()` function. Commit 4014c8475626f20f158921ae0cf98ed259ae4d59 fixes this issue.
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Meta Information
Published
2026-01-07
Last Modified
2026-02-02
Generated
2026-06-16
AI Q&A
2026-01-08
EPSS Evaluated
2026-06-14
NVD
CVE-2026-21851
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
monai monai to 1.5.1 (inc)
project-monai monai to 1.5.1 (exc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-22 The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
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Executive Summary

This vulnerability is a Path Traversal (Zip Slip) issue in MONAI's _download_from_ngc_private() function. The function uses zipfile.ZipFile.extractall() without validating file paths, which can allow an attacker to write files outside the intended directory by crafting malicious zip files. Other similar functions in the codebase properly use a safe extraction method, but this one did not, leading to the vulnerability.

Impact Analysis

An attacker exploiting this vulnerability could potentially overwrite arbitrary files on the system where MONAI is running by extracting files outside the intended directory. This could lead to unauthorized modification of files, impacting the integrity of the system or application.

Mitigation Strategies

Update MONAI to a version later than 1.5.1 where the vulnerability is fixed (commit 4014c8475626f20f158921ae0cf98ed259ae4d59). Avoid using vulnerable versions and ensure that the _download_from_ngc_private() function does not use zipfile.ZipFile.extractall() without path validation.

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