CVE-2026-25587 PUBLISHED

SandboxJS has a Sandbox Escape

Assigner: GitHub_M
Reserved: 03.02.2026 Published: 06.02.2026 Updated: 06.02.2026

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, as Map is in SAFE_PROTOYPES, it's prototype can be obtained via Map.prototype. By overwriting Map.prototype.has the sandbox can be escaped. This vulnerability is fixed in 0.8.29.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 10

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	nyariv
Product	SandboxJS
Versions	Version < 0.8.29 is affected

References

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-66h4-qj4x-38xp
https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3

Problem Types

CWE-94: Improper Control of Generation of Code ('Code Injection') CWE