CVE-2026-25641

The record

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.

Affected packages

Related vulnerabilities

• GHSA-7x3h-rm86-3342 @nyariv/sandboxjs vulnerable to sandbox escape via TOCTOU bug on keys in property accesses Same vulnerability
• CVE-2026-43898 SandboxJS is a JavaScript sandboxing library. Also affects @nyariv/sandboxjs
• GHSA-g8f2-4f4f-5jqw SandboxJS has a sandbox escape via Function.caller leakage of internal call op Also affects @nyariv/sandboxjs
• CVE-2026-34208 SandboxJS is a JavaScript sandboxing library. Also affects @nyariv/sandboxjs
• CVE-2026-34217 SandboxJS is a JavaScript sandboxing library. Also affects @nyariv/sandboxjs
• CVE-2026-34211 SandboxJS is a JavaScript sandboxing library. Also affects @nyariv/sandboxjs
• GHSA-hg73-4w7g-q96w SandboxJS: Sandbox Escape via Prop Object Leak in New Handler Also affects @nyariv/sandboxjs
• GHSA-8pfc-jjgw-6g26 SandboxJS: Stack overflow DoS via deeply nested expressions in recursive descent parser Also affects @nyariv/sandboxjs