CVE-2026-59800

CRITICAL EXPLOITED

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

Title source: cna
STIX 2.1

Exploitation Summary

CVE-2026-59800 has been observed exploited in the wild (reported by VulnCheck KEV).

Description

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).

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-g6g7-pvmx-m74p)
https://github.com/decolua/9router/security/advisories/GHSA-g6g7-pvmx-m74p

Scores

CVSS v3 9.8
EPSS 0.0137
EPSS Percentile 68.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

VulnCheck KEV 2026-07-07
CWE
CWE-78
Status published
Products (3)
decolua/9router < 0.4.44
decolua/9router 0.4.44
npm/9router 0 - 0.4.44npm
Published Jul 07, 2026
Tracked Since Jul 08, 2026