CVE-2026-3884: Spin.js

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

Versions of the package spin.js before 3.0.0 are vulnerable to Cross-site Scripting (XSS) via the spin() function that allows a creation of more than 1 alert for each 'target' element. An attacker would need to set an arbitrary key-value pair on Object.prototype through a crafted URL achieving a prototype pollution first, before being able to execute arbitrary JavaScript in the context of the user's browser.

Affected products

• Spin.js Spin.js: before 3.0.0 (fixed in 3.0.0)

Published 2026-03-11. Last modified 2026-06-17.