CVE-2026-16266
Versions of the package mongo-object before 3.0.3 are vulnerable to Prototype Pollution via the...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-16266- CVSS 4.0
- 6.3 Medium
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 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-1321
- Updated
- 2026-11-02
EUVDEUVD-2026-46151
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.
- Record
EUVD-2026-46151- CVSS 4.0
- 6.3 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-c8xx-jpr5-7m25
Versions of the package mongo-object before 3.0.3 are vulnerable to Prototype Pollution via the...
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.
- Record
GHSA-c8xx-jpr5-7m25- CVSS 4.0
- 6.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-1321
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-16266- CVSS 4.0
- 6.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.0 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Weakness
- CWE-1321
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2026-16266- CVSS 4.0
- 6.3 Medium
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 - Weakness
- CWE-1321
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-16266 is a medium vulnerability (CVSS 6.3), published July 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 37th percentile. No source names a fixed version.
References
security.snyk.io/vuln/SNYK-JS-MONGOOBJECT-13816714
github.com/longshotlabs/mongo-object/issues/27
nvd.nist.gov/vuln/detail/CVE-2026-16266