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Improper Control of Generation of Code ('Code Injection') in happy-dom

CVE-2026-33943

  • happy-dom
High
9.8/10

Summary

A code injection vulnerability in `ECMAScriptModuleCompiler` allows an attacker to achieve Remote Code Execution (RCE) by injecting arbitrary JavaScript expressions inside `export { }` declarations in ES module scripts processed by happy-dom. The compiler directly interpolates unsanitized content into generated code as an executable expression, and the quote filter does not strip backticks, allowing template literal-based payloads to bypass sanitization.

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • NONE
  • NONE
  • HIGH
  • HIGH

CWE-94 - Code Injection

Code injection is a type of vulnerability that allows an attacker to execute arbitrary code. This vulnerability fully compromises the machine and can cause a wide variety of security issues, such as unauthorized access to sensitive information, manipulation of data, denial of service attacks etc. Code injection is different from command injection in the fact that it is limited by the functionality of the injected language (e.g. PHP), as opposed to command injection, which leverages existing code to execute commands, usually within the context of a shell.

References

Advisory Timeline

  • Published