CVE-2026-21851: MONAI (Medical Open Network for AI) is an AI toolkit for health care imaging

Q: How do I fix CVE-2026-21851?

monai: upgrade to newer than 1.5.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-21851 being exploited?

CVE-2026-21851 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-21851 affect?

CVE-2026-21851 affects monai. Severity is medium (CVSS 5.3). 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 `zip

Q: How urgent is CVE-2026-21851?

Priority 31/100. Public exploit reference

Routine

MEDIUM 5.3UPGRADE

CVE-2026-21851 is a medium-severity flaw (CVSS 5.3) affecting monai. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 4014c8475626f20f158921ae0cf98ed

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Weakness	CWE-22
Published	2026-01-07
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: project-monai

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-07 23:15 UTCPublished CVE record published
2026-06-17 10:19 UTCUpdated Record last modified

project-monai monai UPGRADE

Affected: <= 1.5.1

Fixed in: newer than 1.5.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy monai || rpm -q monai || monai --version

2. UPGRADE to newer than 1.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade monai

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade monai

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-21851?

monai: upgrade to newer than 1.5.1. Exact commands for each OS are on this page.

Is CVE-2026-21851 being exploited?

CVE-2026-21851 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-21851 affect?

CVE-2026-21851 affects monai. Severity is medium (CVSS 5.3). 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 `zip

How urgent is CVE-2026-21851?

Priority 31/100. Public exploit reference

References

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