Vulnerability Report

CVE-2026-43898

RCE

Title: SandboxJS sandbox escape via Function.caller

Sandbox Escape, RCE

Proof Of Concept

No public PoC currently indexed for CVE-2026-43898.

CWE Category CWE-94

Published Date May 28, 2026

Modified Date May 28, 2026

Exploit Status Not Found

Score 10.0 CVSS v3.1

Exploit Probability (EPSS)

0.47%

Vulnerability Summary

CVE-2026-43898: SandboxJS is a JavaScript sandboxing library. Prior to 0.9.6, sandbox-defined functions expose Function.caller, allowing sandboxed code to recover the internal LispType.Call runtime callback. That callback can then be invoked with attacker-controlled fake context and obj values to extract blocked host statics, recover the real host Function constructor, and execute arbitrary host JavaScript. This vulnerability is fixed in 0.9.6.

Impacted Vendors

nyariv 1

Reference Links

https://github.com/nyariv/SandboxJS/commit/826865251232611ec94078bab5a18ec875dad4a5 https://github.com/nyariv/SandboxJS/security/advisories/GHSA-g8f2-4f4f-5jqw

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

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-43898 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

May 28, 2026 MODIFIED

Vulnerability data updated via NVD.

May 28, 2026 MODIFIED

Vulnerability data updated via NVD.

May 28, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity LOW

Privileges N/A

Interaction NONE

CVSS Vector String


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

Affected Stack

No specific products linked.