CVE-2018-7166: Node.js

High severity, CVSS 7.5. EPSS: 2.8% chance of exploitation in the next 30 days.

In all versions of Node.js 10 prior to 10.9.0, an argument processing flaw can cause `Buffer.alloc()` to return uninitialized memory. This method is intended to be safe and only return initialized, or cleared, memory. The third argument specifying `encoding` can be passed as a number, this is misinterpreted by `Buffer's` internal "fill" method as the `start` to a fill operation. This flaw may be abused where `Buffer.alloc()` arguments are derived from user input to return uncleared memory blocks that may contain sensitive information.

Affected products

• Node.js Node.js: from 10.0.0, before 10.9.0 (fixed in 10.9.0)

Published 2018-08-21. Last modified 2026-10-08.