# CVE-2021-23334: static-eval arbitrary code execution in function expressions

Source: https://junglewise.ai/threats/cve-2021-23334-static-eval-arbitrary-code-execution-in-function-expressions  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-05-06. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2021-23334 · Severity: low · CVSS 3.1 · Published 2021-05-06

This vulnerability in the static-eval JavaScript library allowed arbitrary code execution through specially crafted function expressions and template literals. The issue was withdrawn after review determined it was not actually a vulnerability in the library itself, but rather a misuse of the library's design—static-eval is intended for evaluating statically-determinable expressions, not untrusted code.

Technologies: [static-eval (npm)](https://junglewise.ai/threats/technologies/static-eval). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2021-23334 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-23334 being exploited in the wild.

**How severe is CVE-2021-23334?** Low severity, with a CVSS score of 3.1, published 6 May 2021.

**Which products and versions are affected?** static-eval (npm) SEMVER:introduced=0,last_affected=2.1.0.

**Is there a fix for CVE-2021-23334?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2021-23334 attacked?** It is attacked over the network.

**Am I affected by CVE-2021-23334?** Check whether you run static-eval (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The static-eval library processes JavaScript AST (Abstract Syntax Tree) nodes to evaluate expressions. A proof-of-concept demonstrated that function expressions and template literals containing eval() calls could be used to achieve arbitrary code execution when processed by the library. However, this was withdrawn because static-eval's documented purpose is to safely evaluate only static expressions; passing untrusted code to it represents misuse rather than a product defect. The vulnerability class would have been improper input validation (CWE-94), but the root cause analysis revealed the issue lay with caller misuse, not the library's intended functionality.

## Affected products

- static-eval static-eval all versions up to 2.1.0

## Identifiers

- CVE-2021-23334
- GHSA-8v27-2fg9-7h62

## Timeline

- 2021-02-11: disclosed: Published to NVD
- 2021-05-06: advisory: Published to OSV
- 2021-05-04: other: Advisory withdrawn

## References

- [https://github.com/browserify/static-eval/blob/master/index.js%23L180](https://github.com/browserify/static-eval/blob/master/index.js%23L180)

## Related threats

- [static-eval arbitrary code execution in function constructor](https://junglewise.ai/threats/static-eval-arbitrary-code-execution-in-function-constructor-d9ad2383)
- [static-eval sandbox breakout / arbitrary code execution](https://junglewise.ai/threats/cve-2017-16226-static-eval-sandbox-breakout-arbitrary-code-execution)