CVE-2025-55292
📋 TL;DR
This vulnerability allows attackers to impersonate legitimate nodes in Meshtastic mesh networks by forging NodeInfo packets that claim HAM mode is enabled. This downgrades security by forcing other nodes to use unencrypted HAM mode communication instead of proper public key cryptography. All Meshtastic users running vulnerable versions are affected.
💻 Affected Systems
- Meshtastic firmware
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of mesh network confidentiality and integrity, allowing attackers to intercept, modify, or block all communications while impersonating legitimate nodes.
Likely Case
Attackers intercept and manipulate communications between specific nodes, potentially accessing sensitive data transmitted over the mesh network.
If Mitigated
Limited impact with proper network segmentation and monitoring, though some data exposure may still occur.
🎯 Exploit Status
Attack requires network access to the mesh but no authentication. The technique is well-documented in the advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.7.6.834c3c5
Vendor Advisory: https://github.com/meshtastic/firmware/security/advisories/GHSA-45vg-3f35-7ch2
Restart Required: Yes
Instructions:
1. Download latest firmware from Meshtastic repository. 2. Flash devices with version 2.7.6.834c3c5 or later. 3. Restart all nodes in the mesh network.
🔧 Temporary Workarounds
Disable HAM mode
allRemove HAM mode from network configuration to prevent the downgrade attack
meshtastic --set-ham-mode false
Network segmentation
allIsolate vulnerable Meshtastic networks from sensitive systems
🧯 If You Can't Patch
- Monitor network for unusual NodeInfo packets or HAM mode activation
- Implement additional authentication layers for critical communications
🔍 How to Verify
Check if Vulnerable:
Check firmware version on all nodes. If version is earlier than 2.7.6.834c3c5, the system is vulnerable.Check Version:
meshtastic --versionVerify Fix Applied:
Confirm all nodes are running version 2.7.6.834c3c5 or later and test that HAM mode cannot be forced by unauthorized nodes.📡 Detection & Monitoring
Log Indicators:
- Multiple NodeInfo updates from same MAC
- Unexpected HAM mode activation
- Node details changing without authorization
Network Indicators:
- Unusual packet patterns with forged NodeInfo
- Encrypted channels switching to unencrypted
SIEM Query:
source="meshtastic" AND (event="nodeinfo_update" AND ham_mode="true")