Secuno
ENNL
Book demo

CVE-2026-34208

Nyariv Sandboxjs vulnerability

10.0 CRITICALPublic exploitEPSS 0.60%
  1. Published6 Apr 2026

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

Affected products

Nyariv Sandboxjs< 0.8.36

Remediation

Fixed in
Nyariv Sandboxjs≥ 0.8.36

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-843198.3
Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the regular…
CVE-2026-843188.8
Nginx UI is a web user interface for the Nginx web server. From 2.0.0-rc.6 until 2.4.1,…
CVE-2026-843178.8
Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1,…
CVE-2026-1091868.8
jshERP through 3.6 contains a mass assignment vulnerability in the UserController…
CVE-2026-1087408.3
GoatCounter through 2.7.0 contains a mass assignment privilege escalation vulnerability…
CVE-2026-169169.1
IBM Security Verify Access 10.0 through 10.0.9.2 and IBM Verify Identity Access 11.0…

Frequently asked

Is CVE-2026-34208 being actively exploited?

CVE-2026-34208 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.60%.

How severe is CVE-2026-34208?

CVE-2026-34208 has a CVSS 3.1 base score of 10.0, rated critical. EPSS estimates a 0.60% probability of exploitation.

Which products are affected by CVE-2026-34208?

Affected products include Nyariv Sandboxjs.

How do I fix CVE-2026-34208?

Upgrade affected software to a fixed version, for example Nyariv Sandboxjs 0.8.36 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-34208 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.