Vulnerability · Published Jun 9, 2026 · Assigned by GitHub_M

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

Medium 6.5

In plain English

A medium-severity security flaw in FlashMQ from halfgaar. 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 23% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 77.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 products (as reported)

Vendor	Product	Versions
halfgaar	FlashMQ	< 1.26.2

Weakness: CWE-248 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-g35r-265r-rxrh x_refsource_CONFIRM
https://github.com/halfgaar/FlashMQ/commit/29e08f7b97b6e3f96db923c2b6a260c47b49c195 x_refsource_MISC
https://github.com/halfgaar/FlashMQ/releases/tag/v1.26.2 x_refsource_MISC