CVE-2025-21608: Meshtastic Firmware

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Meshtastic is an open source mesh networking solution. In affected firmware versions crafted packets over MQTT are able to appear as a DM in client to a node even though they were not decoded with PKC. This issue has been addressed in version 2.5.19 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected products

• Meshtastic Meshtastic Firmware: from 2.5.0, before 2.5.19 (fixed in 2.5.19)

Published 2025-02-18. Last modified 2026-06-17.