CVE-2026-25521
February 04, 2026
Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. In versions from 2.0.12 to before 2.0.39, a prototype pollution vulnerability exists in locutus. Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using String.prototype. This issue has been patched in version 2.0.39.
Affected Packages
https://github.com/locutusjs/locutus.git (GITHUB):
Affected version(s) >=v2.0.12 <v2.0.39Fix Suggestion:
Update to version v2.0.39locutus (NPM):
Affected version(s) >=2.0.12 <2.0.39Fix Suggestion:
Update to version 2.0.39Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.4
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
9.3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
EPSS
Base Score:
0.02
