RCE in Jsonata-Js Jsonata

CVE-2026-77415

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.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

EPSS exploit prediction

EPSS: 0.009 (58.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-77415: held from 0.005 to 0.009.

EPSS over last 30 days · oldest: 0.005 · newest: 0.009 · change: +0.004

Affected products

Weakness classification (CWE)

References