Critical severity · published Aug 21, 2026
CVE-2026-77415
JSONata: Arbitrary Code Execution via crafted JSONata expressions
9.3
CVSS
0.9%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 59% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JS
jsonata · jsonata-js
< 1.8.8; >= 2.0.0, < 2.2.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77415
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-77415
github.com
https://github.com/jsonata-js/jsonata/commit/47c0e58542202c705726663166dbee5fcae47d06
github.com
https://github.com/jsonata-js/jsonata/commit/4b217d514376e30cba278941298d7ba97c4a6c6e
github.com
https://github.com/jsonata-js/jsonata/commit/59e25144fc3b7125f6befd71b8a6e14e1fa610d2
github.com
https://github.com/jsonata-js/jsonata/commit/f09df8416eab8ff44926fc6527c80fb8701de159
github.com
https://github.com/jsonata-js/jsonata/commit/f174348c7fa30f271b63ddedf0767e814004bc4d
github.com
https://github.com/jsonata-js/jsonata/pull/799
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