TI-2026-42621 Aliases CVE-2026-59800 GHSA-g6g7-pvmx-m74p

9Router < 0.4.44 - OS Command Injection via sudoPassword Parameter in Tailscale Install Endpoint

HIGH 75CWE-78Published 2026-07-07 · Updated 2026-07-07

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: Present
Impact type: Code execution, Security bypass
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-78 and CWE-862.

Summary

9Router before 0.4.44 contains an OS command injection vulnerability in the unauthenticated POST /api/tunnel/tailscale-install endpoint (this route is not covered by the dashboard middleware matcher, so no authorization check is applied). The sudoPassword field from the request body is written to the stdin of a 'sudo -S sh' child process. When sudo does not prompt for a password (the process runs as root, NOPASSWD is configured, or a recent sudo timestamp cache exists), the sudoPassword value is interpreted by sh as a shell command, allowing a remote unauthenticated attacker to execute arbitrary OS commands. Exploitation evidence was first observed by the Shadowserver Foundation on 2026-07-04 (UTC).

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.02075 81st percentileScored 2026-11-07

Fix Fixed 9router (decolua): 0.4.449router (npm): 0.4.44

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
decolua	9router	before 0.4.44	0.4.44	Patch available	CNA
—	9router (npm)	before 0.4.44	0.4.44	Patch available	GHSA-g6g7-pvmx-m74p

9router Vendordecolua Affected before 0.4.44 Fixed in 0.4.44 Patch available CNA
9router (npm) Vendor— Affected before 0.4.44 Fixed in 0.4.44 Patch available GHSA-g6g7-pvmx-m74p

Remediation

Fix · CNA 9router (decolua) Fixed in 0.4.44
Fix · GHSA-g6g7-pvmx-m74p 9router (npm) Fixed in 0.4.44 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-59800
2026-10-03 Alias added: GHSA-g6g7-pvmx-m74p

References

Advisory 1

GitHub Security Advisory (GHSA-g6g7-pvmx-m74p)

Other 2

TI-2026-36526 9Router: Hardcoded Default fallback JWT Secret Allows Authentication Bypass CVSS 3.1CRITICAL 9.8
TI-2026-34059 9Router: Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes CVSS 3.1CRITICAL 10.0
TI-2026-44499 9Router 0.4.41 - Unauthenticated API Key Exposure via /api/usage/stats CVSS 4.0CRITICAL 9.3
TI-2026-42622 9Router 0.4.41 - Unauthenticated API Exposure via /api/providers CVSS 4.0CRITICAL 9.3
TI-2026-44500 9Router 0.4.41 - Unauthenticated Information Disclosure via API Usage Endpoints CVSS 4.0HIGH 8.7
TI-2026-40860 9Router: Authenticated Server-Side Request Forgery (SSRF) via OIDC Provider Test Endpoint CVSS 3.1HIGH 8.6

See all 25 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences