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CVE-2026-32640 danthedeckie CVE debrief

The SimpleEval library, used for adding evaluatable expressions to Python projects, has a critical vulnerability (CVE-2026-32640) that allows objects, including modules, to leak dangerous modules through direct access inside the sandbox. This issue, fixed in version 1.0.5, enables attackers to access dangerous functions or modules by passing them as callbacks to safe functions. The vulnerability has a CVSS score of 8.7 and is classified as HIGH severity. The CVE was published on March 16, 2026, and last modified on June 30, 2026.

Vendor
danthedeckie
Product
simpleeval
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-03-16
Original CVE updated
2026-06-30
Advisory published
2026-03-16
Advisory updated
2026-06-30

Who should care

Developers and security teams using the SimpleEval library in their Python projects should be aware of this vulnerability. Given its high severity and potential for exploitation, immediate attention is required to ensure that the library is updated to version 1.0.5 or later. This is particularly crucial for applications that utilize evaluatable expressions and may be exposed to malicious inputs.

Technical summary

CVE-2026-32640 is a vulnerability in the SimpleEval library that allows for the leakage of dangerous modules and execution of disallowed functions. The issue arises from the library's sandboxing mechanism, which can be bypassed by passing objects with modules or disallowed attributes. Attackers can exploit this by providing crafted inputs that lead to the execution of malicious code. The vulnerability is addressed in SimpleEval version 1.0.5. The CVSS vector for this vulnerability is CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

Defensive priority

High priority should be given to updating the SimpleEval library to version 1.0.5 or later. In the interim, defenders should review their codebase for any usage of SimpleEval that could be exploited and consider implementing additional security measures, such as input validation and sandboxing.

Recommended defensive actions

  • Update SimpleEval to version 1.0.5 or later
  • Review and restrict input to SimpleEval expressions
  • Implement additional sandboxing and security measures for evaluatable expressions
  • Monitor for and respond to potential exploitation attempts
  • Conduct a thorough inventory of systems and applications using SimpleEval

Evidence notes

The CVE-2026-32640 vulnerability is confirmed by multiple sources, including the National Vulnerability Database (NVD) and the Common Vulnerabilities and Exposures (CVE) list. The vulnerability is addressed in SimpleEval version 1.0.5, which fixes the issue of dangerous module leaks and execution of disallowed functions. The CVSS score of 8.7 indicates a high severity vulnerability that requires immediate attention.

Official resources

This article is AI-assisted and based on the supplied source corpus.