CVE-2026-33994

Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. Starting in version 2.0.39 and prior to version 3.0.25, a prototype pollution vulnerability exists in the `parse_str` function of the npm package locutus. An attacker can pollute `Object.prototype` by overriding `RegExp.prototype.test` and then passing a crafted query string to `parse_str`, bypassing the prototype pollution guard. This vulnerability stems from an incomplete fix for CVE-2026-25521. The CVE-2026-25521 patch replaced the `String.prototype.includes()`-based guard with a `RegExp.prototype.test()`-based guard. However, `RegExp.prototype.test` is itself a writable prototype method that can be overridden, making the new guard bypassable in the same way as the original — trading one hijackable built-in for another. Version 3.0.25 contains an updated fix.
Configurations

Configuration 1 (hide)

cpe:2.3:a:locutus:locutus:*:*:*:*:*:node.js:*:*

History

01 Apr 2026, 13:22

Type Values Removed Values Added
CPE cpe:2.3:a:locutus:locutus:*:*:*:*:*:node.js:*:*
First Time Locutus
Locutus locutus
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 9.8
References () https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4 - () https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4 - Patch
References () https://github.com/locutusjs/locutus/pull/597 - () https://github.com/locutusjs/locutus/pull/597 - Issue Tracking
References () https://github.com/locutusjs/locutus/releases/tag/v3.0.25 - () https://github.com/locutusjs/locutus/releases/tag/v3.0.25 - Release Notes
References () https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p - () https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p - Exploit, Vendor Advisory

27 Mar 2026, 23:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-03-27 23:17

Updated : 2026-04-01 14:16


NVD link : CVE-2026-33994

Mitre link : CVE-2026-33994

CVE.ORG link : CVE-2026-33994


JSON object : View

Products Affected

locutus

  • locutus
CWE
CWE-1321

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')