CVE-2019-20149
Validation Bypass in kind-of
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
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
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
CVE-2019-20149- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
CVE List No score
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
CVE-2019-20149- Updated
- 2026-11-02
EUVDEUVD-2020-0335 No score
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
EUVD-2020-0335- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-6c8f-qphg-qjgp
Validation Bypass in kind-of
Versions of kind-of 6.x prior to 6.0.3 are vulnerable to a Validation Bypass. A maliciously crafted object can alter the result of the type check, allowing attackers to bypass the type checking validation.
Recommendation
Upgrade to versions 6.0.3 or later.
- Record
GHSA-6c8f-qphg-qjgp- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
OSVAZL-44298
CVE-2019-20149 affecting package js-jquery for versions less than 3.5.0-4
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
AZL-44298- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-05
OSVAZL-47271
CVE-2019-20149 affecting package js-jquery for versions less than 3.5.0-4
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
AZL-47271- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
Show 4 moreShow less
OSV
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
CVE-2019-20149- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2019-20149
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
DEBIAN-CVE-2019-20149- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVGHSA-6c8f-qphg-qjgp
Validation Bypass in kind-of
Versions of kind-of 6.x prior to 6.0.3 are vulnerable to a Validation Bypass. A maliciously crafted object can alter the result of the type check, allowing attackers to bypass the type checking validation.
Recommendation
Upgrade to versions 6.0.3 or later.
- Record
GHSA-6c8f-qphg-qjgp- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-668
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2019-20149
ctorName in index.js in kind-of v6.0.2 allows external user input to overwrite certain internal attributes via a conflicting name, as demonstrated by 'constructor': {'name':'Symbol'}. Hence, a crafted payload can overwrite this builtin attribute to manipulate the type detection result.
- Record
UBUNTU-CVE-2019-20149- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
kind-ofnpm |
6.0.0 up to 6.0.3 | 6.0.3 |
js-jqueryAzure Linux:3 |
before 3.5.0-4 | 3.5.0-4 |
js-jqueryAzure Linux:2 |
before 3.5.0-4 | 3.5.0-4 |
node-kind-ofDebian:12 |
before 6.0.3+dfsg-1 | 6.0.3+dfsg-1 |
node-kind-ofDebian:13 |
before 6.0.3+dfsg-1 | 6.0.3+dfsg-1 |
node-kind-ofDebian:14 |
before 6.0.3+dfsg-1 | 6.0.3+dfsg-1 |
node-kind-ofUbuntu:18.04:LTS |
All versions, plus listed versions 3.0.4+dfsg-16.0.1+dfsg-16.0.2+dfsg-1 |
None known |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | mrknowledgshare/testing_cve-2019-20149 | 2026-02-27 |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | OSV | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-20149 is a high vulnerability (CVSS 7.5) in Kind-of Project Kind-of, published December 30, 2019. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 2.34%, the 83rd percentile. Fixed in kind-of 6.0.3.