CVE-2026-53676Network attack vector

Host code execution via cross-realm argument prototype

Published Jun 17, 2026 · Updated Jun 17, 2026

Prototype pollution in ThingsBoard before 4.3.1.2 allows remote authenticated users to execute code in the JS executor host process. The tb-js-executor invokeScript path passes a host-realm args array into the VM sandbox, enabling traversal through args.constructor.constructor to the host Function constructor. Exploitation requires TENANT_ADMIN access and use_sandbox=true; successful execution exposes host files, shell commands, and environment variables.

CVSS severity8.6
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in ThingsBoard before 4.3.1.2 allows remote authenticated users to execute code in the JS executor host process. The tb-js-executor invokeScript path passes a host-realm args array into the VM sandbox, enabling traversal through args.constructor.constructor to the host Function constructor. Exploitation requires TENANT_ADMIN access and use_sandbox=true; successful execution exposes host files, shell commands, and environment variables.

The record

CVE
CVE-2026-53676
Published
Jun 17, 2026
Updated
Jun 17, 2026
Vendor
ThingsBoard
Product
ThingsBoard
Classifications
CWE-1321, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=prior to v4.3.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ThingsBoard · ThingsBoardversion=prior to v4.3.1.2

Published CVSS scores

8.6JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
7.2JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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