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.
References
| Link | Resource |
|---|---|
| https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4 | Patch |
| https://github.com/locutusjs/locutus/pull/597 | Issue Tracking |
| https://github.com/locutusjs/locutus/releases/tag/v3.0.25 | Release Notes |
| https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p | Exploit Vendor Advisory |
| https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p | Exploit Vendor Advisory |
| https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p | Exploit Vendor Advisory |
| https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p | Exploit Vendor Advisory |
Configurations
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 : v3 : |
v2 : unknown
v3 : 9.8 |
| References | () https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4 - Patch | |
| References | () https://github.com/locutusjs/locutus/pull/597 - Issue Tracking | |
| References | () https://github.com/locutusjs/locutus/releases/tag/v3.0.25 - Release Notes | |
| References | () 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')
