decolua 9Router up to 0.4.43 Tailscale Install tailscale-install sudoPassword os command injection

Summaryinfo

A vulnerability has been found in decolua 9Router up to 0.4.43 and classified as very critical. Affected by this vulnerability is an unknown functionality of the file /api/tunnel/tailscale-install of the component Tailscale Install Handler. The manipulation of the argument sudoPassword leads to os command injection. This vulnerability is listed as CVE-2026-59800. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in decolua 9Router up to 0.4.43 and classified as very critical. This issue affects an unknown part of the file /api/tunnel/tailscale-install of the component Tailscale Install Handler. The manipulation of the argument sudoPassword with an unknown input leads to a os command injection vulnerability. Using CWE to declare the problem leads to CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE 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 advisory is shared at github.com. The identification of this vulnerability is CVE-2026-59800 since 07/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/07/2026). MITRE ATT&CK project uses the attack technique T1202 for this issue.

Upgrading to version 0.4.44 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• decolua

Name

• 9Router

Version

• 0.4.0
• 0.4.1
• 0.4.2
• 0.4.3
• 0.4.4
• 0.4.5
• 0.4.6
• 0.4.7
• 0.4.8
• 0.4.9
• 0.4.10
• 0.4.11
• 0.4.12
• 0.4.13
• 0.4.14
• 0.4.15
• 0.4.16
• 0.4.17
• 0.4.18
• 0.4.19
• 0.4.20
• 0.4.21
• 0.4.22
• 0.4.23
• 0.4.24
• 0.4.25
• 0.4.26
• 0.4.27
• 0.4.28
• 0.4.29
• 0.4.30
• 0.4.31
• 0.4.32
• 0.4.33
• 0.4.34
• 0.4.35
• 0.4.36
• 0.4.37
• 0.4.38
• 0.4.39
• 0.4.40
• 0.4.41
• 0.4.42
• 0.4.43

Website

• Product: https://github.com/decolua/9router/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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