CVE-2026-77415

Critical

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.

SeverityCritical

CVSS9.3

Exploit probability—

ProductJsonata

PublishedAug 21, 2026

First seenAug 21, 2026

Weakness typeCWE-94Code injection

How to fix

Update

jsonata2.2.1, 1.8.8 or later

Affected products

Product	Affected versions	Fixed in
jsonatanpm	2.0.0 ≤ v < 2.2.1, v < 1.8.8	2.2.1, 1.8.8

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