CVE-2026-34217

HIGH

SandboxJS has a Sandbox Escape via Prop Object Leak in New Handler

Title source: cna
STIX 2.1

Description

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.36, a scope modification vulnerability exists in @nyariv/sandboxjs. The vulnerability allows untrusted sandboxed code to leak internal interpreter objects through the new operator, exposing sandbox scope objects in the scope hierarchy to untrusted code; an unexpected and undesired exploit. While this could allow modifying scopes inside the sandbox, code evaluation remains sandboxed and prototypes remain protected throughout the execution. This vulnerability is fixed in 0.8.36.

Scores

CVSS v3 7.2
EPSS 0.0007
EPSS Percentile 20.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-668
Status published
Products (3)
nyariv/sandboxjs < 0.8.36
nyariv/sandboxjs 0 - 0.8.36npm
nyariv/SandboxJS < 0.8.36
Published Apr 06, 2026
Tracked Since Apr 06, 2026