CVSS 3.1
10.0 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HCVE-2026-25881
Critical (10.0) in nyariv sandboxjs. EPSS 0.6% chance of exploitation in the next 30 days. Fixed in @nyariv/sandboxjs 0.8.31.
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.31, a sandbox escape vulnerability allows sandboxed code to mutate host built-in prototypes by laundering the isGlobal protection flag through array literal intermediaries. When a global prototype reference (e.g., Map.prototype, Set.prototype) is placed into an array and retrieved, the isGlobal taint is stripped, permitting direct prototype mutation from within the sandbox. This results in persistent host-side prototype pollution and may enable RCE in applications that use polluted properties in sensitive sinks (example gadget: execSync(obj.cmd)). This vulnerability is fixed in 0.8.31.
Severity
- EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-31)
- CWE
- CWE-1321
- Published
- Modified
- Record from
- the NVD, synced
Affected
- nyariv:sandboxjs
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-ww7g-4gwx-m7wj | npm | @nyariv/sandboxjs | <0.8.31 | 0.8.31 |