nyariv SandboxJS up to 0.8.28 Map.prototype.has code injection

Summaryinfo

A vulnerability classified as critical was found in nyariv SandboxJS up to 0.8.28. The impacted element is the function Map.prototype.has. The manipulation results in code injection. This vulnerability is identified as CVE-2026-25587. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in nyariv SandboxJS up to 0.8.28. Affected is the function Map.prototype.has. The manipulation with an unknown input leads to a code injection vulnerability. CWE is classifying the issue as CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-25587 since 02/03/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.

Upgrading to version 0.8.29 eliminates this vulnerability. Applying the patch 67cb186c41c78c51464f70405504e8ef0a6e43c3 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-5590). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• nyariv

Name

• SandboxJS

Version

• 0.8.0
• 0.8.1
• 0.8.2
• 0.8.3
• 0.8.4
• 0.8.5
• 0.8.6
• 0.8.7
• 0.8.8
• 0.8.9
• 0.8.10
• 0.8.11
• 0.8.12
• 0.8.13
• 0.8.14
• 0.8.15
• 0.8.16
• 0.8.17
• 0.8.18
• 0.8.19
• 0.8.20
• 0.8.21
• 0.8.22
• 0.8.23
• 0.8.24
• 0.8.25
• 0.8.26
• 0.8.27
• 0.8.28

License

• open-source

Website

• Product: https://github.com/nyariv/SandboxJS/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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