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.
History

Thu, 05 Feb 2026 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Locutus
Locutus locutus
Vendors & Products Locutus
Locutus locutus

Wed, 04 Feb 2026 21:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Locutus is vulnerable to Prototype Pollution
Weaknesses CWE-1321
References
Metrics cvssV4_0

{'score': 9.4, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-02-04T21:20:32.643Z

Updated: 2026-02-04T21:20:32.643Z

Reserved: 2026-02-02T18:21:42.487Z

Link: CVE-2026-25521

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-04T22:15:59.203

Modified: 2026-02-04T22:15:59.203

Link: CVE-2026-25521

cve-icon Redhat

No data.