jsonata-js JSONata up to 1.8.7/2.2.0 src/jsonata.js environment.lookup prototype pollution

Summaryinfo

A vulnerability classified as critical has been found in jsonata-js JSONata up to 1.8.7/2.2.0. The impacted element is the function environment.lookup of the file src/jsonata.js. This manipulation causes prototype pollution. This vulnerability is registered as CVE-2026-77414. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in jsonata-js JSONata up to 1.8.7/2.2.0. It has been declared as critical. Affected by this vulnerability is the function environment.lookup of the file src/jsonata.js. The manipulation with an unknown input leads to a prototype pollution vulnerability. The CWE definition for the vulnerability is CWE-1321. The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE 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 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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-77414 since 08/20/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059 for this issue.

Upgrading to version 1.8.8 or 2.2.1 eliminates this vulnerability.

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Productinfo

Vendor

• jsonata-js

Name

• JSONata

Version

• 1.8.0
• 1.8.1
• 1.8.2
• 1.8.3
• 1.8.4
• 1.8.5
• 1.8.6
• 1.8.7
• 2.0
• 2.1
• 2.2.0

Website

• Product: https://github.com/jsonata-js/jsonata/

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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