{"id":"CVE-2024-27307","aliases":["GHSA-fqg8-vfv7-8fj8"],"url":"https://o3.security/vulnerability/CVE-2024-27307","summary":"JSONata expression can pollute the \"Object\" prototype","details":"### Impact\n\nIn JSONata versions `>= 1.4.0, < 1.8.7` and `>= 2.0.0, < 2.0.4`, a malicious expression can use the [transform operator](https://docs.jsonata.org/other-operators#-------transform) to override properties on the `Object` constructor and prototype. This may lead to denial of service, remote code execution or other unexpected behavior in applications that evaluate user-provided JSONata expressions.\n\n### Patch\n\nThis issue has been fixed in JSONata versions `>= 1.8.7` and `>= 2.0.4`. Applications that evaluate user-provided expressions should update ASAP to prevent exploitation. The following patch can be applied if updating is not possible.\n\n```patch\n--- a/src/jsonata.js\n+++ b/src/jsonata.js\n@@ -1293,6 +1293,13 @@ var jsonata = (function() {\n                 }\n                 for(var ii = 0; ii < matches.length; ii++) {\n                     var match = matches[ii];\n+                    if (match && (match.isPrototypeOf(result) || match instanceof Object.constructor)) {\n+                        throw {\n+                            code: \"D1010\",\n+                            stack: (new Error()).stack,\n+                            position: expr.position\n+                        };\n+                    }\n                     // evaluate the update value for each match\n                     var update = await evaluate(expr.update, match, environment);\n                     // update must be an object\n@@ -1539,7 +1546,7 @@ var jsonata = (function() {\n                 if (typeof err.token == 'undefined' && typeof proc.token !== 'undefined') {\n                     err.token = proc.token;\n                 }\n-                err.position = proc.position;\n+                err.position = proc.position || err.position;\n             }\n             throw err;\n         }\n@@ -1972,6 +1979,7 @@ var jsonata = (function() {\n         \"T1007\": \"Attempted to partially apply a non-function. Did you mean ${{{token}}}?\",\n         \"T1008\": \"Attempted to partially apply a non-function\",\n         \"D1009\": \"Multiple key definitions evaluate to same key: {{value}}\",\n+        \"D1010\": \"Attempted to access the Javascript object prototype\", // Javascript specific \n         \"T1010\": \"The matcher function argument passed to function {{token}} does not return the correct object structure\",\n         \"T2001\": \"The left side of the {{token}} operator must evaluate to a number\",\n         \"T2002\": \"The right side of the {{token}} operator must evaluate to a number\",\n```\n\n### References\n\nhttps://github.com/jsonata-js/jsonata/releases/tag/v2.0.4\n\n### Credit\n\nThank you to Albert Pedersen of Cloudflare for disclosing this issue.\n","published":"2024-03-06T19:24:16.876Z","modified":"2026-08-12T03:51:16.254860627Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"jsonata","fixedVersion":"1.8.7"},{"ecosystem":"npm","name":"jsonata","fixedVersion":"2.0.4"}],"fix":{"url":"https://github.com/jsonata-js/jsonata/commit/1d579dbe99c19fbe509f5ba2c6db7959b0d456d1","label":"jsonata-js/jsonata@1d579db"},"references":[{"type":"WEB","url":"https://github.com/jsonata-js/jsonata/releases/tag/v2.0.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/27xxx/CVE-2024-27307.json"},{"type":"ADVISORY","url":"https://github.com/jsonata-js/jsonata/security/advisories/GHSA-fqg8-vfv7-8fj8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-27307"},{"type":"FIX","url":"https://github.com/jsonata-js/jsonata/commit/1d579dbe99c19fbe509f5ba2c6db7959b0d456d1"},{"type":"FIX","url":"https://github.com/jsonata-js/jsonata/commit/335d38f6278e96c908b24183f1c9c90afc8ae00c"},{"type":"FIX","url":"https://github.com/jsonata-js/jsonata/commit/c907b5e517bb718015fcbd993d742ba6202f2be2"},{"type":"PACKAGE","url":"https://github.com/jsonata-js/jsonata"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:16.254860627Z"}}