Answer in brief
CVE-2026-126495 records a Medium severity (CVSS 5.3) vulnerability in MQTTX through 1.13.3 Stored XSS via Topic Tree and JSON Tree Tooltips. The current sources do not mark it as known exploited. The current feed maps emqx/MQTTX (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps emqx/MQTTX (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| emqx/MQTTXgeneric | >=0 <=1.13.3 | Not reported |
Published upstream
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 11, 2026
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.
Quoted source text, attributed separately from HOL analysis.