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Fencer Intel
high 8.8

CVE-2018-3723 json

Prototype Pollution in defaults-deep

published 2018-06-07 8 y ago modified 2026-06-17 4 mo ago also GHSA-cqp5-m4pq-gfgp , EUVD-2018-0261

cvss
8.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

defaults-deep node module before 0.2.4 suffers from a Modification of Assumed-Immutable Data (MAID) vulnerability, which allows a malicious user to modify the prototype of "Object" via __proto__, causing the addition or modification of an existing property that will exist on all objects.

Patch / fix

  • npm defaults-deep 0.2.4
  • defaults-deep_project defaults-deep 0.2.4

Exploit prediction

2.00% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/310514 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P
GitHub 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm defaults-deep
<0.2.4
0.2.4

Affected products

  • HackerOne defaults-deep node module

Classification

Weakness
  • CWE-471 Modification of Assumed-Immutable Data (MAID)
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.