CVE-2025-21608Network attack vector

Message spoofing via unchecked MQTT packet provenance

Published Feb 18, 2025 · Updated Feb 19, 2025

Message spoofing in Meshtastic Firmware 2.5.0 through 2.5.18 allows remote attackers to inject forged direct messages over MQTT. The MQTT packet-handling path forwards crafted packets into direct-message clients without confirming that PKC decoded them. MQTT ingestion must be enabled and a recipient must view the message; the reported impact is false message attribution, not code execution or disclosure.

CVSS severity5.3
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Message spoofing in Meshtastic Firmware 2.5.0 through 2.5.18 allows remote attackers to inject forged direct messages over MQTT. The MQTT packet-handling path forwards crafted packets into direct-message clients without confirming that PKC decoded them. MQTT ingestion must be enabled and a recipient must view the message; the reported impact is false message attribution, not code execution or disclosure.

The record

CVE
CVE-2025-21608
Published
Feb 18, 2025
Updated
Feb 19, 2025
Vendor
Meshtastic
Product
Meshtastic Firmware
Classifications
CWE-668, T1565.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 19, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.5.0, <= 2.5.18

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Meshtastic · Meshtastic Firmwareversion=>= 2.5.0, <= 2.5.18

Published CVSS scores

5.3NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
5.3GitHub, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1565.002Transmitted Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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