High severity · published Sep 27, 2026
CVE-2026-100842
MONAI through 1.6.0 _get_fake_spatial_shape eval() Sandbox Bypass via Attribute Chains
8.8
CVSS
0.2%
EPSS
No
On KEV
Description
MONAI through 1.6.0 contains an eval injection vulnerability in _get_fake_spatial_shape() in monai/bundle/scripts.py. The function validates shape expressions with a helper that walks the AST and only collects ast.Name nodes, rejecting any name other than 'p' or 'n', before passing the string to eval(). Expressions built solely from constants and attribute, subscript, or call nodes (for example "(1).__class__.__bases__[0].__subclasses__()" or "int.__class__.__init__.__globals__") contain no ast.Name nodes and therefore bypass the allowlist. Because the shape value originates from bundle metadata consumed by _get_real_input_data and verify_net_in_out (reachable through the bundle 'verify_net_in_out' CLI flow), an attacker who can influence a bundle's metadata can escape the eval sandbox via object introspection chains and achieve code execution in this non-default flow.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
MONAI · Project-MONAI
through 1.6.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-100842
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-100842
vendor-advisory
https://github.com/Project-MONAI/MONAI/security/advisories/GHSA-h89g-r5pc-wxfm
third-party-advisory
https://www.vulncheck.com/advisories/monai-through-1.6.0-get-fake-spatial-shape-eval-sandbox-bypass-via-attribute-chains
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