FlashMQ does not release memory of queued QoS messages
Priority LOW 20CWE-772Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-772.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00341 27th percentileScored 2026-11-07
Fix Fixed FlashMQ (halfgaar): 1.23.2
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
Remediation
- Fix · CNA FlashMQ (halfgaar) Fixed in 1.23.2
Timeline
- 2026-10-02 Threatist record created from CVE-2025-62723
References
More halfgaar vulnerabilities
- TI-2026-30530 FlashMQ: Division by zero crash when using non-default deferred retained message setting CVSS 3.1MEDIUM 6.5
- TI-2026-34125 FlashMQ: Client can trigger uncaught exception on FlashMQ 1.26.1 and older CVSS 3.1MEDIUM 6.5
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences