Vulnerability · Published Oct 16, 2025 · Assigned by GitHub_M

CVE-2025-62413MQTTX vulnerable to cross-site scripting via improper message payload rendering

Medium 6.1

In plain English

A medium-severity cross-site scripting in MQTTX from emqx. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities).

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.3%top 74.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

MQTTX is an MQTT 5.0 desktop client and MQTT testing tool. A Cross-Site Scripting (XSS) vulnerability was introduced in MQTTX v1.12.0 due to improper handling of MQTT message payload rendering. Malicious payloads containing HTML or JavaScript could be rendered directly in the MQTTX message viewer. If exploited, this could allow attackers to execute arbitrary scripts in the context of the application UI — for example, attempting to access MQTT connection credentials or trigger unintended actions through script injection. This vulnerability is especially relevant when MQTTX is used with brokers in untrusted or multi-tenant environments, where message content cannot be fully controlled. This vulnerability is fixed in 1.12.1.

Affected products (as reported)

Vendor	Product	Versions
emqx	MQTTX	= 1.12.0

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

https://github.com/emqx/MQTTX/security/advisories/GHSA-29gf-9r9v-j4m3 x_refsource_CONFIRM
https://github.com/emqx/MQTTX/commit/2963f78a4b3227cdb93597f546a75b75dee1059f x_refsource_MISC