Zoltán Papp 91d4f61284 [client] Reject metrics ingest bodies whose peer_id tag disagrees with the header
validateTag checked tag names against the per-measurement allowlist but only
bounded the value length, so the peer_id tag was free-form text up to 64 bytes
and could differ from the X-Peer-ID header the request was accepted with.

Tie the two together: the tag value must equal the header value. Since the
header is already checked to be 16 hex characters, this transitively constrains
the tag to the same shape. Every client sends the same value in both places
(metrics.go feeds agentInfo.peerID to both push.SetPeerID and the body tags),
so well-behaved clients are unaffected.

The mismatch is rejected rather than silently overwritten: rewriting the value
would re-serialize caller-controlled text back into line protocol and would
hide misbehaving senders instead of surfacing them. Rejection also matches the
other input validation failures in the same handler, which all return 400.

This narrows the value space of the peer_id tag but does not by itself bound
InfluxDB series cardinality: a sender that puts the same arbitrary 16 hex
characters in both the header and the body still passes. Limiting that needs a
per-source rate limit in front of the service.
2026-08-31 17:21:02 +02:00
2026-08-01 08:17:03 +09:00

Start using NetBird at netbird.io
See Documentation
Join our Slack channel or our Community forum


🚀 We are hiring! Join us at https://netbird.io/careers

🤖 NetBird Agent Network (Beta)

Identity-aware access control for AI agents — keyless access to LLM APIs and private resources over the encrypted NetBird tunnel. See agent-network/ or read the docs at netbird.ai.

NetBird combines a configuration-free peer-to-peer private network and a centralized access control system in a single platform, making it easy to create secure private networks for your organization or home.

Connect. NetBird creates a WireGuard-based overlay network that automatically connects your machines over an encrypted tunnel, leaving behind the hassle of opening ports, complex firewall rules, VPN gateways, and so forth.

Secure. NetBird enables secure remote access by applying granular access policies while allowing you to manage them intuitively from a single place. Works universally on any infrastructure.

https://github.com/user-attachments/assets/10cec749-bb56-4ab3-97af-4e38850108d2

Self-host NetBird (video)

Watch the video

Key features

Connectivity Management Security Automation Platforms
✓ Kernel WireGuard ✓ Admin Web UI ✓ SSO & MFA support ✓ Public API ✓ Linux
✓ Peer-to-peer connections ✓ Auto peer discovery and configuration ✓ Access control: groups & rules ✓ Setup keys for bulk provisioning ✓ macOS
✓ Connection relay fallback ✓ IdP integrations ✓ Activity logging ✓ Self-hosting quickstart script ✓ Windows
✓ Routes to external networks ✓ Private DNS ✓ Traffic events ✓ IdP groups sync with JWT ✓ Android
✓ Domain-based DNS routes ✓ Custom DNS zones ✓ Device posture checks ✓ Terraform provider ✓ Android TV
✓ Exit nodes ✓ Multiuser support ✓ Peer-to-peer encryption ✓ Ansible collection ✓ iOS
✓ IPv6 dual-stack overlay ✓ Multi-account profile switching ✓ SSH with central access policies ✓ Apple TV
✓ Browser SSH & RDP ✓ Quantum-resistance with Rosenpass ✓ FreeBSD
✓ Reverse proxy with auto-TLS ✓ Periodic re-authentication ✓ pfSense
✓ OPNsense
✓ MikroTik RouterOS
✓ OpenWRT
✓ Synology
✓ TrueNAS
✓ Proxmox
✓ Raspberry Pi
✓ Serverless
✓ Container

Quickstart with NetBird Cloud

Quickstart with self-hosted NetBird

This is the quickest way to try self-hosted NetBird. It should take around 5 minutes to get started if you already have a public domain and a VM. Follow the Advanced guide with a custom identity provider for installations with different IdPs.

Infrastructure requirements:

  • A Linux VM with at least 1 CPU and 2 GB of memory.
  • The VM should be publicly accessible on TCP ports 80 and 443 and UDP port 3478.
  • A public domain name pointing to the VM.

Software requirements:

Steps

  • Download and run the installation script:
export NETBIRD_DOMAIN=netbird.example.com; curl -fsSL https://github.com/netbirdio/netbird/releases/latest/download/getting-started.sh | bash

A bit on NetBird internals

  • Every machine in the network runs the NetBird agent, which manages WireGuard.
  • Every agent connects to the Management Service, which holds network state, manages peer IPs, and distributes updates to agents.
  • Agents use ICE (via pion/ice) to discover connection candidates for peer-to-peer connections.
  • Candidates are discovered with the help of STUN servers.
  • Agents negotiate a connection through the Signal Service, exchanging end-to-end encrypted messages with candidates.
  • When NAT traversal fails (e.g. mobile carrier-grade NAT) and a direct p2p connection isn't possible, the system falls back to a Relay Service and a secure WireGuard tunnel is established through it.

NetBird high-level architecture diagram

See a complete architecture overview for details.

Community projects

Note: The main branch may be in an unstable or even broken state during development. For stable versions, see releases.

Support acknowledgement

In November 2022, NetBird joined the StartUpSecure program sponsored by the Federal Ministry of Education and Research of the Federal Republic of Germany. Together with the CISPA Helmholtz Center for Information Security, NetBird brings security best practices and simplicity to private networking.

CISPA_Logo_BLACK_EN_RZ_RGB (1)

Acknowledgements

We build on open source technologies like WireGuard®, Pion ICE, and Rosenpass. We greatly appreciate the work these projects are doing, and we'd love it if you could support them too (e.g., by starring or contributing).

This repository is licensed under the BSD-3-Clause license, which applies to all parts of the repository except for the directories management/, signal/ and relay/. Those directories are licensed under the GNU Affero General Public License version 3.0 (AGPLv3). See the respective LICENSE files inside each directory.

WireGuard and the WireGuard logo are registered trademarks of Jason A. Donenfeld.

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