What is the CVSS score of CVE-2026-25587?

CVE-2026-25587 has a CVSS 3.1 base score of 10.0 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of Sandboxjs are affected by CVE-2026-25587?

SandboxJS versions prior to 0.8.29 contain a critical sandbox escape vulnerability (CVSS 10.0) that allows attackers to bypass JavaScript execution restrictions and execute arbitrary code.. A patch is available.

Is there a public PoC exploit available for CVE-2026-25587?

Yes, a public proof-of-concept exploit is available for CVE-2026-25587. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-25587?

Within 24 hours: Identify all systems and applications using SandboxJS and assess their exposure to untrusted code sources. Within 7 days: Upgrade SandboxJS to version 0.8.29 or later across all affected systems and validate the patch in staging environments. Within 30 days: Conduct a security audit of systems that were running vulnerable versions to detect any potential exploitation and review access logs for suspicious activity.

Sandboxjs CVE-2026-25587

CRITICAL

Code Injection (CWE-94)

2026-02-06 security-advisories@github.com

GHSA-66h4-qj4x-38xp

Code Injection RCE Sandboxjs

10.0

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

10.0 CRITICAL

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

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Feb 18, 2026 - 14:31 vuln.today

Public exploit code

Patch released

Feb 18, 2026 - 14:31 nvd

Patch available

CVE Published

Feb 06, 2026 - 20:16 nvd

CRITICAL 10.0

DescriptionGitHub Advisory

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.