CVE-2026-25587: @nyariv/sandboxjs has a Sandbox Escape vulnerability

February 5, 2026 (updated February 6, 2026)

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.

References

github.com/advisories/GHSA-66h4-qj4x-38xp
github.com/nyariv/SandboxJS
github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3
github.com/nyariv/SandboxJS/security/advisories/GHSA-66h4-qj4x-38xp
nvd.nist.gov/vuln/detail/CVE-2026-25587

Code Behaviors & Features

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