CVE-2026-54737: Phun-Ky Defaults-Deep

High severity, CVSS 7.3. EPSS: 0.5% chance of exploitation in the next 30 days.

@phun-ky/defaults-deep is a library like lodash defaultsDeep with array preservation and no lodash dependency. Prior to 2.0.5, defaultsDeep() recursively merges user-supplied objects without filtering proto, constructor, and prototype, allowing properties to be written to Object.prototype. This issue is fixed in version 2.0.5.

Affected products

• Phun-Ky Defaults-Deep: before 2.0.5 (fixed in 2.0.5)

Published 2026-07-31. Last modified 2026-09-10.