Checkov: ASTEVAL Allows Malicious Tampering of Exposed AST Nodes Leads to Sandbox Escape
Affects checkovSource GCVE Database
CVSS 8.4 High : upgrade to 3.2.490 soon.
Data as of 18 Sep 2026, 01:37 UTC
- Patch
- Available – fixed in 3.2.490
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWhat to do
Upgrade checkov to 3.2.490.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewcheckovpkg:brew/checkovOther threats | Affected
| Fixed in
|
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AI-suggested
A patch is available for this vulnerability. Users should upgrade to a fixed version of the asteval library as incorporated in Checkov versions 3.2.490 and later. Until patched, avoid processing untrusted input with asteval or restrict usage contexts to trusted environments. Review vendor advisories for the official fix and apply updates promptly.
Description
A vulnerability in the asteval library used by Checkov allows attackers who can control input to bypass safety checks and execute arbitrary Python code. The flaw arises because the attribute access verification can be circumvented by modifying AST nodes at runtime, exploiting a time-of-check to time-of-use (TOCTOU) issue. Specifically, the Procedure class exposes its AST in an unprotected attribute, enabling attackers to alter the AST and access dangerous dunder methods like __getattribute__. This leads to sandbox escape and arbitrary code execution within the application's context.