Vulnerability Report

CVE-2026-25641

Title: Sandbox escape in SandboxJS due to key mismatch

Arbitrary File Access

Proof Of Concept

No public PoC currently indexed for CVE-2026-25641.

CWE Category CWE-367

Published Date Feb 06, 2026

Modified Date Feb 18, 2026

Exploit Status Not Found

Score 10.0 CVSS v3.1

Exploit Probability (EPSS)

0.49%

Vulnerability Summary

CVE-2026-25641: SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used, e.g., one for the time the key is sanitized using hasOwnProperty(key) and a different one for when the key is used for the actual property access. This vulnerability is fixed in 0.8.29.

Impacted Vendors

nyariv 1

Reference Links

https://github.com/nyariv/SandboxJS/blob/6103d7147c4666fe48cfda58a4d5f37005b43754/src/executor.ts#L304-L304 https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3 https://github.com/nyariv/SandboxJS/security/advisories/GHSA-7x3h-rm86-3342

CVSS v3.1

Source Entity [email protected]

Severity CRITICAL

10.0

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H