---
title: "CVE-2026-77414: JSONata vulnerable to Arbitrary Code Execution via crafted JSONata expressions"
url: https://erroneo.us/security/cve/CVE-2026-77414/
description: "CVE-2026-77414 (jsonata (npm)): JSONata is a JSON query and transformation language. Prior to 1.8.8 and 2.2.1, the src/jsonata.js environment.lookup…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-21
date_modified: 2026-08-26
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-77414"
kev: false
cvss: 9.3
epss: 0.0057
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-77414: JSONata vulnerable to Arbitrary Code Execution via crafted JSONata expressions

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6% , percentile 46: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 46% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes jsonata (npm) >= 2.0.0, < 2.2.1, fixed in 2.2.1 ; jsonata (npm) < 1.8.8, fixed in 1.8.8 . Check your lockfile, including transitive dependencies.

## What it is

JSONata is a JSON query and transformation language. Prior to 1.8.8 and 2.2.1, the src/jsonata.js environment.lookup function used a bypassable hasOwnProperty check. Crafted expressions could use $hasOwnProperty, $spread, $string, prototype access, and $constructor to reach the object prototype and invoke process.getBuiltinModule with childprocess, executing arbitrary code with the privileges of the host process. This issue is fixed in versions 1.8.8 and 2.2.1.

## Affected packages

- npm `jsonata` >= 2.0.0, < 2.2.1 → fixed: 2.2.1
- npm `jsonata` < 1.8.8 → fixed: 1.8.8

## Affected products (CVE record)

- jsonata-js jsonata: < 1.8.8, >= 2.0.0, < 2.2.1

## Severity

- GitHub_M CVSS 4.0: 9.3 `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`
- GitHub CVSS 4.0: 9.3 `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`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.57% probability of exploitation activity in the next 30 days; percentile 46.

## Sources

- [GitHub Advisory GHSA-2943-5xfg-gq5f](https://github.com/advisories/GHSA-2943-5xfg-gq5f)
- [CVE.org record CVE-2026-77414](https://www.cve.org/CVERecord?id=CVE-2026-77414)
- [NVD entry CVE-2026-77414](https://nvd.nist.gov/vuln/detail/CVE-2026-77414)
- [github.com](https://github.com/jsonata-js/jsonata/security/advisories/GHSA-2943-5xfg-gq5f)
- [github.com](https://github.com/jsonata-js/jsonata/pull/799)
- [github.com](https://github.com/jsonata-js/jsonata/commit/59e25144fc3b7125f6befd71b8a6e14e1fa610d2)
- [github.com](https://github.com/jsonata-js/jsonata/releases/tag/v1.8.8)
- [github.com](https://github.com/jsonata-js/jsonata/releases/tag/v2.2.1)
- [github.com](https://github.com/jsonata-js/jsonata/commit/c41ef185136a7b96ca1049c7745a7503b82193de)
- [github.com](https://github.com/jsonata-js/jsonata/commit/f09df8416eab8ff44926fc6527c80fb8701de159)

---
Source page: https://erroneo.us/security/cve/CVE-2026-77414/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt