Description
JSONata is a JSON query and transformation language. Prior to 1.8.8 and 2.2.0, the src/functions.js lookup function lacked an Object.prototype.hasOwnProperty check and allowed crafted expressions to access inherited prototype members. An attacker able to supply an expression could use inherited prototype setters and getters, constructor access, valueOf, and process.getBuiltinModule to reach the child_process module and execute arbitrary code with the privileges of the host process. This issue is fixed in versions 1.8.8 and 2.2.0.
References7
- github.com/jsonata-js/jsonata/commit/4b217d514376e30cba27894129…
- github.com/jsonata-js/jsonata/commit/4c5f4adfb90a9b500889d50f90…
- github.com/jsonata-js/jsonata/pull/794
- github.com/jsonata-js/jsonata/releases/tag/v1.8.8
- github.com/jsonata-js/jsonata/releases/tag/v2.2.0
- github.com/jsonata-js/jsonata/security/advisories/GHSA-8gq3-vp5…
- github.com/jsonata-js/jsonata/security/advisories/GHSA-8gq3-vp5…
Metrics
- CVSS 4.0
-
9.3
CRITICAL
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 54 · as of 9 November 2026
- CWE
- CWE-94
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.