CVE-2026-25881: 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…

PriorityP356critical10CVSS 3.1

AVNACLPRNUINSCCHIHAH

EPSS

0.55%

41.9th percentile

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.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
nyariv	sandboxjs	< 0.8.31	0.8.31
nyariv	sandboxjs	>= 0 < 0.8.31	0.8.31

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.