Prototype Pollution in async merge-object

Also known as GHSA-fp82-2h99-3fpp

Published 8 y ago 2018-07-03 · modified 4 mo ago 2026-06-17 · JSON

CVSS

9.8

v3.0 · NVD

CISA KEV

not known exploited

EPSS

1.4%

percentile 73%

Public exploits

none known

The utilities function in all versions <= 1.0.0 of the merge-objects node module can be tricked into modifying the prototype of Object when the attacker can control part of the structure passed to this function. This can let an attacker add or modify existing properties that will exist on all objects.

Exploit prediction (EPSS)

1.43% probability of exploitation in the next 30 days, higher than 73% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
NVD	3.0	9.8	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
NVD	2.0	7.5	`AV:N/AC:L/Au:N/C:P/I:P/A:P`
GitHub	3.0	9.8	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

Affected packages

Ecosystem	Package	Affected	Fixed in
npm	`merge-object`	<=1.0.0	no fix listed

Classification

Weakness

CWE-20 Improper Input Validation
CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

hackerone.com /reports/310706 · x_refsource_MISC, x_transferred
nvd.nist.gov /vuln/detail/CVE-2018-3753 · advisory

Sources

CVE List: CVE-2018-3753
GitHub Advisory: GHSA-fp82-2h99-3fpp
NVD: CVE-2018-3753

vulnwire keeps one entry per vulnerability: the CVE id wins, then GHSA; records that alias each other are merged. Machine-readable: JSON.