CVE-2026-43898

SandboxJS is a JavaScript sandboxing library. Prior to 0.9.6, sandbox-defined functions expose Function.caller, allowing sandboxed code to recover the internal LispType.Call runtime callback. That callback can then be invoked with attacker-controlled fake context and obj values to extract blocked host statics, recover the real host Function constructor, and execute arbitrary host JavaScript. This vulnerability is fixed in 0.9.6.

CVSS 3.1

10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-25)

CWE

CWE-94

Published

2026-05-28

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• nyariv:sandboxjs

Packages (OSV)

References

• https://github.com/nyariv/SandboxJS/commit/826865251232611ec94078bab5a18ec875dad4a5
• https://github.com/nyariv/SandboxJS/security/advisories/GHSA-g8f2-4f4f-5jqw
• https://github.com/nyariv/SandboxJS/security/advisories/GHSA-g8f2-4f4f-5jqw

Check your stackJSON