Vulnerability · Published Dec 29, 2025 · Assigned by GitHub_M
CVE-2025-53627Meshtastic firmware allows forged DMs with no PKC to show up as encrypted
Medium 5.3
In plain English
A medium-severity security flaw in firmware from meshtastic. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).
Official description
Meshtastic is an open source mesh networking solution. The Meshtastic firmware (starting from version 2.5) introduces asymmetric encryption (PKI) for direct messages, but when the `pki_encrypted` flag is missing, the firmware silently falls back to legacy AES-256-CTR channel encryption. This was an intentional decision to maintain backwards compatibility. However, the end-user applications, like Web app, iOS/Android app, and applications built on top of Meshtastic using the SDK, did not have a way to differentiate between end-to-end encrypted DMs and the legacy DMs. This creates a downgrade attack path where adversaries who know a shared channel key can craft and inject spoofed direct messages that are displayed as if they were PKC encrypted. Users are not given any feedback of whether a direct message was decrypted with PKI or with legacy symmetric encryption, undermining the expected security guarantees of the PKI rollout. Version 2.7.15 fixes this issue.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| meshtastic | firmware | >= 2.5, < 2.7.15 |
Weakness: CWE-1287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://github.com/meshtastic/firmware/security/advisories/GHSA-377p-prwp-4hwf x_refsource_CONFIRM