FlashMQ: Client can trigger uncaught exception on FlashMQ 1.26.1 and older
CVE-2026-46411

6.5MEDIUM

Key Information:

Vendor

Halfgaar

Status
FlashMQ
Vendor
CVE Published:
9 June 2026

What is CVE-2026-46411?

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.

Affected Version(s)

FlashMQ < 1.26.2

References

https://github.com/halfgaar/FlashMQ/security/advisories/G...
x_refsource_CONFIRM
https://github.com/halfgaar/FlashMQ/commit/29e08f7b97b6e3...
x_refsource_MISC
https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.2
x_refsource_MISC

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.