Medium

Improperly Controlled Modification of Dynamically-Determined Object Attributes in express-mock-middleware

  • Disclosed: 09.12.2021
  • Updated: 11.10.2026 10:22

express-mock-middleware through 0.0.6 is vulnerable to Prototype Pollution. Exported functions by the package can be tricked into adding or modifying properties of the Object.prototype. Exploitation of this vulnerability requires creation of a new directory where an attack code can be placed which will then be exported by express-mock-middleware. As such, this is considered to be a low risk.

Affected software

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PlatformPackageVulnerable versionsFixed in
npm package express-mock-middleware <= 0.0.6 no fix

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE)
CWE-1321, CWE-915
Platform
npm
Package
express-mock-middleware
Disclosed
09.12.2021
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-v39h-qm32-8gwq - CC BY 4.0

Vulnerability history: express-mock-middleware

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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