Locutus is vulnerable to Prototype Pollution_CVE-2026-25521

9.4 / 10

CRITICAL

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

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.

Basic Information

ID CVE-2026-25521

Source GitHub_M

Published Feb 4, 2026 at 21:20

Affected Product

Vendor locutusjs

Product locutus

Version >= 2.0.12, < 2.0.39

Affected Versions locutusjs locutus >= 2.0.12, < 2.0.39

CWE Classification

CWE-1321

References

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    "published": "2026-02-04T21:20:32.643Z",
    "modified": "2026-02-04T21:20:32.643Z",
    "type": "cve",
    "title": "Locutus is vulnerable to Prototype Pollution",
    "source": "GitHub_M",
    "references": "https://github.com/locutusjs/locutus/security/advisories/GHSA-rxrv-835q-v5mh\nhttps://github.com/locutusjs/locutus/commit/042af9ca7fde2ff599120783e720a17f335bb01c",
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