Threats affecting pkg:github/halfgaar/FlashMQ

CVE-2026-46411 is a vulnerability in halfgaar FlashMQ, an MQTT broker/server. Prior to version 1.26.2, authorized clients could cause the server to abort by exceeding the allowed write buffer over-commit, triggering an uncaught internal exception. This issue has been fixed in version 1.26.2.

FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.26.1, a remote client with retained publish permission can crash the FlashMQ broker when both set_retained_message_defer_timeout and set_retained_message_defer_timeout_spread are configured to non-default values, resulting in denial of service. If anonymous retained publishing is allowed, no authentication is required; otherwise, the attacker needs the corresponding publish permission. This issue has been patched in version 1.26.1.

FlashMQ is a MQTT broker/server, designed for multi-CPU environments. Prior to version 1.23.2, any authenticated user can create sessions and have them collect QoS messages. When not sent to a client, these are then not released upon (eventual) session expiration. Version 1.23.2 fixes the issue.