Skip to main content
VulnerabilityPublished

CVE-2026-34208: nyariv SandboxJS · Protection Mechanism Failure

Affects nyariv SandboxJSSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 10.0 Critical : upgrade to 0.8.36 as a priority.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score
10.0Critical
How severe the flaw is on the 0–10 CVSS scale.

Contested

Critical score, yet low EPSS after six months
EPSS
0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 0.8.36
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 6 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade SandboxJS and nyariv/sandboxjs to 0.8.36.

Affected software

ProductAffectedFixed in
nyarivSandboxJSAffected
  • <0.8.36
Fixed in
  • 0.8.36
npmnyariv/sandboxjspkg:npm/nyariv/sandboxjsOther threatsAffected
  • <0.8.36
Fixed in
  • 0.8.36

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade SandboxJS to version 0.8.36 or later, where this vulnerability is fixed. Since the vulnerability is resolved in this version, no additional mitigation steps are required beyond applying the update. Patch status is not explicitly stated in the vendor advisory, but the description confirms the fix is included in version 0.8.36.

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.

References

Community reviews

Loading reviews…