CVE-2026-100842 PUBLISHED

MONAI through 1.6.0 _get_fake_spatial_shape eval() Sandbox Bypass via Attribute Chains

Assigner: VulnCheck
Reserved: 26.09.2026 Published: 27.09.2026 Updated: 27.09.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.3

Product Status

Vendor Project-MONAI
Product MONAI
Versions Default: unaffected
  • affected from 0 to 1.6.0 (incl.)

References

Problem Types

  • Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') CWE