CVE-2026-77415

Received Received - Intake

Code Execution via JSONata Expression Manipulation

Publication date: 2026-08-21

Last updated on: 2026-08-21

Assigner: GitHub, Inc.

Description

JSONata is a JSON query and transformation language. Prior to 1.8.8 and 2.2.1, crafted JSONata expressions could chain several object-integrity weaknesses to execute arbitrary code. The chain could overwrite $clone to mutate objects through evaluateTransformExpression, expose and deconstruct JSONata functions or lambdas through $merge.*, replace proc.arguments.forEach used by applyProcedure, and forge internal lambda state. These primitives allowed an attacker to reach prototype getters, prototype and constructor access, and process.getBuiltinModule with child_process, executing code with the privileges of the host process. This issue is fixed in versions 1.8.8 and 2.2.1.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-21

Last Modified

2026-08-21

Generated

2026-08-22

AI Q&A

2026-08-22

EPSS Evaluated

N/A

NVD

CVE-2026-77415

Affected Vendors & Products

Vendor	Product	Version / Range
jsonata	jsonata	to 1.8.8 (inc)
jsonata	jsonata	to 2.2.1 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-94	The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

Attack-Flow Graph

Executive Summary

JSONata versions before 1.8.8 and 2.2.1 have a vulnerability where crafted expressions can chain multiple object-integrity weaknesses to execute arbitrary code. Attackers can overwrite internal functions and manipulate objects to reach prototype getters and execute code with the host process privileges.

Detection Guidance

Detecting this vulnerability requires checking the version of JSONata in use. If your system uses JSONata versions prior to 1.8.8 or 2.2.1, it is vulnerable. Commands to check the version depend on the environment, such as npm list jsonata or checking package.json for the installed version.

Impact Analysis

If exploited, this vulnerability allows attackers to run arbitrary code on your system with the same permissions as the JSONata process. This could lead to data theft, system compromise, or unauthorized access depending on the application's context.

Compliance Impact

This vulnerability could lead to unauthorized data access or exfiltration, violating GDPR's data protection principles and HIPAA's security requirements. Organizations using vulnerable versions may face compliance violations and legal consequences.

Mitigation Strategies

Immediately upgrade JSONata to version 1.8.8 or 2.2.1 or later. If upgrading is not possible, review and restrict input handling for JSONata expressions to prevent crafted inputs from being processed. Additionally, audit applications using JSONata for potential exploitation attempts.

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