Skip to main content
CVE-2026-25520VulnerabilityPublished

CVE-2026-25520: nyariv SandboxJS · Injection

Affects nyariv SandboxJSSource CVE Database V5

0

Not known to be exploited · CVSS 10.0 Critical : upgrade to 0.8.29 as a priority.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score
10.0Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 0.8.29
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 6 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: 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 2026-10-25.

What to do

Upgrade SandboxJS and nyariv/sandboxjs to 0.8.29.

Affected software

ProductAffectedFixed in
nyarivSandboxJSAffected
  • <0.8.29
Fixed in
  • 0.8.29
npmnyariv/sandboxjspkg:npm/nyariv/sandboxjsOther threatsAffected
  • <0.8.29
Fixed in
  • 0.8.29

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

AI-suggested

1. Immediately upgrade all instances of SandboxJS to version 0.8.29 or later, where the vulnerability is fixed. 2. Audit all applications and services to identify usage of SandboxJS and verify the version in use. 3. Implement runtime monitoring and anomaly detection to identify suspicious JavaScript execution patterns indicative of sandbox escapes. 4. Employ defense-in-depth by restricting network access and privileges of services using SandboxJS to limit potential damage from exploitation. 5. Review and harden Content Security Policies (CSP) to reduce the risk of malicious script injection. 6. Conduct penetration testing focused on sandbox escape techniques to validate the effectiveness of mitigations. 7. Stay informed on any emerging exploits or patches related to this vulnerability. 8. For environments where immediate patching is not feasible, consider disabling or isolating SandboxJS usage temporarily until patched.

Description

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, The return values of functions aren't wrapped. Object.values/Object.entries can be used to get an Array containing the host's Function constructor, by using Array.prototype.at you can obtain the hosts Function constructor, which can be used to execute arbitrary code outside of the sandbox. This vulnerability is fixed in 0.8.29.

References

Community reviews

Loading reviews…