NetBird client SSH config Match line injection via peer FQDN or hostname allows local command execution
Summary
| CVE | CVE-2026-105429 |
|---|---|
| State | PUBLISHED |
| Assigner | securin |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-14 05:16:42 UTC |
| Updated | 2026-10-14 05:16:42 UTC |
| Description | Improper neutralization of special elements in the NetBird client SSH configuration manager (client/ssh/config/manager.go) in NetBird versions 0.60.0 through 0.74.6 allows a malicious or compromised peer to execute arbitrary commands on other NetBird client hosts. The client writes a system-wide OpenSSH drop-in file (/etc/ssh/ssh_config.d/99-netbird.conf, or the equivalent under %PROGRAMDATA%\ssh\ssh_config.d on Windows) that embeds each peer FQDN or hostname inside a double-quoted Match host directive without escaping. A peer name containing a double quote breaks out of the quoted context and injects arbitrary SSH configuration directives, including exec commands, which run locally as any user on the host the next time that user runs ssh. Desktop clients on Linux, macOS, Windows and FreeBSD are affected; the Android and iOS apps are not. The issue is fixed in version 0.74.7, which accepts a peer FQDN or hostname only if it is a valid DNS name. |
Risk And Classification
Primary CVSS: v4.0 8.9 HIGH from 33c584b5-0579-4c06-b2a0-8d8329fcab9c
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-78 | CWE-116 | CWE-78 CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') | CWE-116 CWE-116 Improper Encoding or Escaping of Output
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | Secondary | 8.9 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 8.9 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| 3.1 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | Secondary | 8 | HIGH | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8 | HIGH | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/netbirdio/netbird/pull/6805 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | github.com | |
| github.com/netbirdio/netbird/releases/tag/v0.74.7 | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | github.com | |
| github.com/netbirdio/netbird/security/advisories/GHSA-xmg2-v32j-x2hf | 33c584b5-0579-4c06-b2a0-8d8329fcab9c | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Arjun Basnet from Securin (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-13T00:00:00.000Z | Reported to the vendor through a GitHub Security Advisory |
| CNA | 2026-07-15T00:00:00.000Z | Vendor accepted the report |
| CNA | 2026-07-17T00:00:00.000Z | Fix released in version 0.74.7 |
| CNA | 2026-09-01T00:00:00.000Z | Vendor advisory GHSA-xmg2-v32j-x2hf published |
| CNA | 2026-10-05T00:00:00.000Z | CVE ID assigned |
Solutions
CNA: Upgrade the NetBird client to version 0.74.7 or later. In this version, buildHostPatterns accepts a peer FQDN or hostname only if it is a plain DNS name, and rejects quotes, whitespace, newlines, commas and SSH pattern metacharacters (pull request #6805).