Memory corruption vulnerability in QMqttClient impacts Qt MQTT
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in Qt 6.8.9, Qt 6.11.3, Qt 6.12.0
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Certain MQTT 5 connection settings between client and server Affected Qt versions: Qt 5.12.0 to Qt 6.8.8, and Qt 6.9.0 to Qt 6.11.2
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 14/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in Qt 6.8.9, Qt 6.11.3, Qt 6.12.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
The Qt MQTT module's QMqttClient class, used by applications that communicate over MQTT, is affected by a memory corruption flaw. When certain MQTT 5 connection settings are used between client and server, the application can crash.
Read the original 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.
What to do
Check whether your setup matches what the bug needs.
Certain MQTT 5 connection settings between client and server Affected Qt versions: Qt 5.12.0 to Qt 6.8.8, and Qt 6.9.0 to Qt 6.11.2Upgrade to a fixed version: Qt 6.8.9, Qt 6.11.3, Qt 6.12.0.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- qt Qt
From 5.12.0 · through 6.8.8; From 6.9.0 · through 6.11.2
Evidence 2
- Advisory
- Patch
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-107457
What does this mean?
QMqttClient, the Qt MQTT client component, can corrupt memory under certain MQTT 5 connection settings between client and server. This can crash the application that uses it.Source: wiki.qt.io
Am I affected, and how do I check?
Qt 5.12.0 through 6.8.8 and Qt 6.9.0 through 6.11.2 are listed as affected. The problem only arises with certain MQTT 5 connection settings, so check your Qt version and whether your application uses QMqttClient with MQTT 5.Source: wiki.qt.io
What should I do about it?
Upgrade to a fixed release: Qt 6.8.9, Qt 6.11.3, or Qt 6.12.0, depending on your release branch.Source: wiki.qt.io
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data