CVE-2026-59800CWE-78

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

Critical · published July 7, 2026

CVSS v4.0
9.2
EPSS
2%
Percentile
81.0
In the wild
Unconfirmed
What it is

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).

The record
Technical detail
CVSS v4.0
9.2 · CRITICAL
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.02043 · 81.0th percentile
Weakness
CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Published
2026-07-07T18:19Z
EPSS history
Timeline
  • 07 JUL 18:19Z
    9Router < 0.4.44 - OS Command Injection via sudoPassword Parameter in Tailscale Install Endpoint
    cvelistv5