Prototype Pollution in Phun-Ky Defaults-Deep
CVE-2026-54737
@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.
Vulnerability class: Prototype Pollution
EPSS: 0.003 (18.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
Affected products
- Phun-ky Defaults-deep — versions < 2.0.5
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-54737?
- CVE-2026-54737 is a high-severity vulnerability in Phun-Ky Defaults-Deep, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.3/10. Published 2026-07-31.
- How severe is CVE-2026-54737?
- High severity. CVSS v3 base score is 7.3 out of 10.