---
id: "CVE-2026-126495"
page: "https://infrastack.ai/live/CVE-2026-126495"
kind: "vulnerability"
aliases: ["CVE-2026-126495"]
title: "MQTTX desktop: stored XSS via MQTT topics runs script in app"
severity: "medium"
cvss: 6.1
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["desktop", "electron", "mqtt", "mqttx", "other"]
not_affected_if: ["not-desktop-app", "trusted-brokers-only"]
published_at: "2026-11-11T01:17:14+00:00"
first_seen_at: "2026-11-11T01:24:33+00:00"
updated_at: "2026-11-11T01:25:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126495", "first_seen_at": "2026-11-11T01:24:33+00:00"}]
exploit_sources: []
---

# MQTTX desktop: stored XSS via MQTT topics runs script in app

Link for people: https://infrastack.ai/live/CVE-2026-126495 (this .md is for agents)

MQTTX desktop, an MQTT client app, renders MQTT topic names and payloads unescaped in tooltips. An attacker who controls a broker or can publish to a subscribed topic can run script in the app's Electron renderer when a user hovers over a Topic Tree or JSON tree node.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed MQTTX desktop version against the affected range `through 1.13.3`
- Confirm whether you subscribe to brokers or topics you do not fully trust

## Timeline

- 2026-11-11T01:24:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126495

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/mqttx-through-1.13.3-stored-xss-via-topic-tree-and-json-tree-tooltips

## From the sources

MQTTX desktop through 1.13.3 contains a stored cross-site scripting vulnerability that allows attackers to inject script by publishing malicious MQTT topic names or payloads rendered unescaped in tooltips. Attackers controlling a broker or publishing to subscribed topics can execute script in the Electron renderer, which has nodeIntegration enabled, when victims hover Topic Tree or JSON tree nodes.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_