by Kastro
Paper/Archive/CVE-2026-43898

CVE-2026-43898

nyariv SandboxJS — SandboxJS: Sandbox escape via Function.caller leakage of internal call op

EPSS 0.5%public exploitCVSS 10.0
critical.is priorityof 100
48
CVSS 10.0 (CNA)10.0 / 10 × 3030.0Not in CISA KEV+300.0EPSS percentile 40.9.409 × 208.2Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
SandboxJS< 0.9.6–CNA

Scores by source

GitHub_M (CNA)10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: yes · Technical impact: total

References

exploitgithub.com/nyariv/SandboxJS/security/advisories/GHSA-g8f2-4f4f-5jqwrefgithub.com/nyariv/SandboxJS/commit/826865251232611ec94078bab5a18ec875dad4a5