What is CVE-2025-21608?

CVE-2025-21608 is a medium-severity vulnerability in Meshtastic Firmware, classified under Exposure of Resource to Wrong Sphere. CVSS score: 5.3/10. Published 2025-02-18.

How severe is CVE-2025-21608?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Meshtastic Firmware

CVE-2025-21608

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.

Published 2025-02-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (29.6th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Meshtastic Firmware — versions >= 2.5.0, <= 2.5.18
Meshtastic Firmware

Weakness classification (CWE)

CWE-668 — Exposure of Resource to Wrong Sphere

References

github.com/meshtastic/firmware/security/advisories/GHSA-c967-qc39-3hf5 (Third Party Advisory)

Frequently asked questions

What is CVE-2025-21608?: CVE-2025-21608 is a medium-severity vulnerability in Meshtastic Firmware, classified under Exposure of Resource to Wrong Sphere. CVSS score: 5.3/10. Published 2025-02-18.
How severe is CVE-2025-21608?: Medium severity. CVSS v3 base score is 5.3 out of 10.