Skip to content
Fencer Vulns
high 7.5

CVE-2021-23329 json

Prototype Pollution

published 2021-01-31 5 y ago modified 2026-07-08 4 mo ago also GHSA-c497-v8pv-ch6x , EUVD-2021-0543

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

The package nested-object-assign before 1.0.4 are vulnerable to Prototype Pollution via the default function, as demonstrated by running the PoC below.

Patch / fix

  • npm nested-object-assign 1.0.4
  • n/a nested-object-assign 1.0.4

Exploit prediction

1.54% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/Geta/NestedObjectAssign/pull/11 referenced PoC, tagged "exploit" by a source, unverified
  • snyk.io https://snyk.io/vuln/SNYK-JS-NESTEDOBJECTASSIGN-1065977 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm nested-object-assign
<1.0.4
1.0.4

Affected products

  • n/a nested-object-assign

Classification

Weakness
  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns 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.