CVE-2026-16266

Prototype Pollution via expandKey in mongo-object

Published Jul 21, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
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__.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Longshotlabs
Longshotlabs mongo-object
Vendors & Products Longshotlabs
Longshotlabs mongo-object
Type Values Removed Values Added
Title Prototype Pollution via expandKey in mongo-object
Type Values Removed Values Added
Title Prototype Pollution via expandKey in mongo-object Package
Type Values Removed Values Added
Title Prototype Pollution via expandKey in mongo-object Package
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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__.
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N'}

cvssV4_0

{'score': 6.3, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
snyk
Published
Updated
Jul 21, 2026, 2:52 PM
Reserved
Jul 20, 2026, 8:55 AM
Status
Awaiting Analysis
Published
Jul 21, 2026, 6:16 AM
Modified
Jul 23, 2026, 3:48 PM