CVE-2026-34208
CRITICALDescription
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.36, SandboxJS blocks direct assignment to global objects (for example Math.random = ...), but this protection can be bypassed through an exposed callable constructor path: this.constructor.call(target, attackerObject). Because this.constructor resolves to the internal SandboxGlobal function and Function.prototype.call is allowed, attacker code can write arbitrary properties into host global objects and persist those mutations across sandbox instances in the same process. This vulnerability is fixed in 0.8.36.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
Exploit Intelligence
Moderate risk: more likely to be exploited than 44% of all known CVEs.
References
Related Vulnerabilities
Other CWE-693 (Protection Mechanism Failure) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2013-2465 | Critical | 9.8 | 99% | KEV + Ransom | - |
| CVE-2024-21412 | High | 8.1 | 95% | KEV + Ransom | Fix |
| CVE-2013-0431 | Medium | 5.3 | 90% | KEV + Ransom | - |
| CVE-2019-1003030 | Critical | 9.9 | 76% | KEV | - |
| CVE-2025-40536 | High | 8.1 | 72% | KEV | Fix |
| CVE-2025-0411 | High | 7.0 | 67% | KEV | Fix |
Common questions
How do I fix CVE-2026-34208?
Upgrade sandboxjs to 0.8.36 or later.
Is CVE-2026-34208 being actively exploited?
Not that we know of. CVE-2026-34208 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.56% is the estimated probability that it will be exploited in the next 30 days. That is higher than 44% of all scored CVEs.
How severe is CVE-2026-34208?
CVE-2026-34208 has a CVSS v3 base score of 10.0, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-34208 affect?
Published advisories record a fix for sandboxjs (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-34208
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-09.