nyariv SandboxJS up to 0.8.28 toctou

Summaryinfo

A vulnerability identified as critical has been detected in nyariv SandboxJS up to 0.8.28. This affects an unknown part. This manipulation causes toctou. This vulnerability is handled as CVE-2026-25641. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in nyariv SandboxJS up to 0.8.28 and classified as critical. Affected by this vulnerability is some unknown functionality. The manipulation with an unknown input leads to a toctou vulnerability. The CWE definition for the vulnerability is CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-25641 since 02/04/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

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-2026-5589). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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