What is CVE-2026-25587?

CVE-2026-25587 is a critical-severity vulnerability in Nyariv Sandboxjs, classified under Code Injection. CVSS score: 10.0/10. Published 2026-02-06.

How severe is CVE-2026-25587?

Critical severity. CVSS v3 base score is 10.0 out of 10.

RCE in Nyariv Sandboxjs

CVE-2026-25587

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, 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. This vulnerability is fixed in 0.8.2…

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.000 (10.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Nyariv Sandboxjs — versions < 0.8.29

Weakness classification (CWE)

CWE-94 — Code Injection

References

https://github.com/nyariv/SandboxJS/security/advisories/GHSA-66h4-qj4x-38xp (x_refsource_CONFIRM)
https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-25587?: CVE-2026-25587 is a critical-severity vulnerability in Nyariv Sandboxjs, classified under Code Injection. CVSS score: 10.0/10. Published 2026-02-06.
How severe is CVE-2026-25587?: Critical severity. CVSS v3 base score is 10.0 out of 10.