---
title: "CVE-2024-27307: JSONata expression can pollute the \"Object\" prototype"
url: https://erroneo.us/security/cve/CVE-2024-27307/
description: "CVE-2024-27307 (jsonata (npm)): JSONata is a JSON query and transformation language. Starting in version 1.4.0 and prior to version 1.8.7 and 2.0.4, a…"
type: vulnerability-record
section: "Security Digest"
date_published: 2024-03-06
date_modified: 2024-08-13
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2024-27307"
kev: false
cvss: 9.8
epss: 0.01422
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2024-27307: JSONata expression can pollute the "Object" prototype

**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?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 1.4% , percentile 73: FIRST’s model estimates a 1.4% chance of exploitation activity in the next 30 days, higher than 73% of all scored CVEs (moderate). 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) >= 1.4.0, < 1.8.7, fixed in 1.8.7 ; jsonata (npm) >= 2.0.0, < 2.0.4, fixed in 2.0.4 . Check your lockfile, including transitive dependencies.

## What it is

JSONata is a JSON query and transformation language. Starting in version 1.4.0 and prior to version 1.8.7 and 2.0.4, a malicious expression can use the transform operator 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. This 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. As a workaround, one may apply the patch manually.

## Affected packages

- npm `jsonata` >= 1.4.0, < 1.8.7 → fixed: 1.8.7
- npm `jsonata` >= 2.0.0, < 2.0.4 → fixed: 2.0.4

## Affected products (CVE record)

- jsonata-js jsonata: >= 1.4.0, < 1.8.7, >= 2.0.0, < 2.0.4

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.42% probability of exploitation activity in the next 30 days; percentile 73.

## Sources

- [GitHub Advisory GHSA-fqg8-vfv7-8fj8](https://github.com/advisories/GHSA-fqg8-vfv7-8fj8)
- [CVE.org record CVE-2024-27307](https://www.cve.org/CVERecord?id=CVE-2024-27307)
- [NVD entry CVE-2024-27307](https://nvd.nist.gov/vuln/detail/CVE-2024-27307)
- [github.com](https://github.com/jsonata-js/jsonata/security/advisories/GHSA-fqg8-vfv7-8fj8)
- [github.com](https://github.com/jsonata-js/jsonata/commit/1d579dbe99c19fbe509f5ba2c6db7959b0d456d1)
- [github.com](https://github.com/jsonata-js/jsonata/commit/335d38f6278e96c908b24183f1c9c90afc8ae00c)
- [github.com](https://github.com/jsonata-js/jsonata/commit/c907b5e517bb718015fcbd993d742ba6202f2be2)
- [github.com](https://github.com/jsonata-js/jsonata/releases/tag/v2.0.4)

---
Source page: https://erroneo.us/security/cve/CVE-2024-27307/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt