{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "2.0.39"
              },
              {
                "fixed": "3.0.25"
              }
            ]
          },
          "events": [
            {
              "introduced": "fb90ed0cb832897ef15880be446ab124e3313047"
            },
            {
              "fixed": "0d2402bdb92f9c59918114af9c8ba628f22e9152"
            }
          ],
          "repo": "https://github.com/locutusjs/locutus",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-vc8f-x9pp-wf5p"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-1321"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33994.json"
  },
  "details": "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.",
  "id": "CVE-2026-33994",
  "modified": "2026-04-01T23:08:47.619905497Z",
  "published": "2026-03-27T22:15:47.131Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33994.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4"
    },
    {
      "type": "FIX",
      "url": "https://github.com/locutusjs/locutus/pull/597"
    },
    {
      "type": "WEB",
      "url": "https://github.com/locutusjs/locutus/releases/tag/v3.0.25"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/locutusjs/locutus/security/advisories/GHSA-vc8f-x9pp-wf5p"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33994"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Locutus Prototype Pollution due to incomplete fix for CVE-2026-25521"
}