CVE-2026-16266 PUBLISHED

Assigner: snyk
Reserved: 20.07.2026 Published: 21.07.2026 Updated: 21.07.2026

Versions of the package mongo-object before 3.0.3 are vulnerable to Prototype Pollution via the expandKey() function in util.js. An attacker can modify the JavaScript prototype chain by supplying a crafted property path containing special keys such as proto.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
CVSS Score: 6.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	n/a
Product	mongo-object
Versions	affected from 0 to 3.0.3 (excl.)

Credits

Dezhen Kong

References

https://security.snyk.io/vuln/SNYK-JS-MONGOOBJECT-13816714
https://github.com/longshotlabs/mongo-object/issues/27
https://github.com/longshotlabs/mongo-object/blob/4f7a570f2a2fcfa9417b7870d5f859e9574ec73c/src/util.ts%23L251
https://github.com/longshotlabs/mongo-object/commit/638314107d8b397e5453c28e41729522b3e8d67c

Problem Types

Prototype Pollution