Vulnerability · Published Nov 2, 2026 · Assigned by Qt

CVE-2026-107457Memory corruption vulnerability in QMqttClient impacts Qt MQTT

Low 2.3

In plain English

A low-severity out-of-bounds write in Qt from qt. 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 18% of all known vulnerabilities).

Severity (CVSS 4.0)2.3Low
Exploit odds (30 days)0.3%top 81.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

A memory corruption vulnerability in the QMqttClient class of the Qt MQTT module. Under certain MQTT 5 connection settings between client and server, QMqttClient may corrupt memory, which can cause the application to crash.

Affected products (as reported)

VendorProductVersions
qt Qt 5.12.0 – through 6.8.86.9.0 – through 6.11.2

Weakness: CWE-787, CWE-129 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/R:U/RE:L/U:Green

References