TI-2026-34125 Aliases CVE-2026-46411

FlashMQ: Client can trigger uncaught exception on FlashMQ 1.26.1 and older

LOW 29CWE-248Published 2026-06-09 · Updated 2026-06-10

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-248.

Summary

FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.26.2, authorized clients have the ability to exceed the permitted over-commit of their write buffer and triggering an internal safe-guard exception. This exception was in a path that was not catchable, and therefore causes a server abort. This issue has been patched in version 1.26.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00301 23rd percentileScored 2026-11-07

Fix Fixed FlashMQ (halfgaar): 1.26.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
halfgaar	FlashMQ	before 1.26.2	1.26.2	Patch available	CNA

FlashMQ Vendorhalfgaar Affected before 1.26.2 Fixed in 1.26.2 Patch available CNA

Remediation

Fix · CNA FlashMQ (halfgaar) Fixed in 1.26.2

Timeline

2026-10-02 Threatist record created from CVE-2026-46411

References

Other 3

TI-2026-30530 FlashMQ: Division by zero crash when using non-default deferred retained message setting CVSS 3.1MEDIUM 6.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences