Is CVE-2026-126495 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-126495 being exploited in the wild.

How severe is CVE-2026-126495?

Medium severity, with a CVSS score of 6.1, published 11 November 2026.

Which products and versions are affected?

EMQ MQTTX desktop through 1.13.3.

Is there a fix for CVE-2026-126495?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-126495 attacked?

It is attacked over the network.

Am I affected by CVE-2026-126495?

Check whether you run EMQ MQTTX desktop at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-126495: MQTTX desktop stored cross-site scripting in tooltips

CVE-2026-126495 · Severity: medium · CVSS 6.1 · Published 2026-11-11

MQTTX is a desktop application for connecting to and testing MQTT message brokers. An attacker who controls an MQTT broker or can publish messages can inject malicious scripts into topic names or message payloads. When users hover over topics or data in the application, the unescaped content executes as code with full system access, potentially allowing remote code execution.

Vendors: EMQ.

Quick answers

Is CVE-2026-126495 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-126495 being exploited in the wild.
How severe is CVE-2026-126495?: Medium severity, with a CVSS score of 6.1, published 11 November 2026.
Which products and versions are affected?: EMQ MQTTX desktop through 1.13.3.
Is there a fix for CVE-2026-126495?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-126495 attacked?: It is attacked over the network.
Am I affected by CVE-2026-126495?: Check whether you run EMQ MQTTX desktop at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stored cross-site scripting vulnerability exists in MQTTX's rendering of MQTT topic names and message payloads in tooltips. Malicious scripts injected via topic names or payloads are rendered unescaped in the Electron renderer process, which has nodeIntegration enabled, allowing script execution. An attacker must control a broker or have publish access to subscribed topics, and a victim must hover over an affected node to trigger the vulnerability.

Affected products

EMQ MQTTX desktop through 1.13.3

Timeline

2026-11-11: disclosed

References

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