# CVE-2026-59800: decolua 9Router OS command injection in tailscale-install endpoint

Source: https://junglewise.ai/threats/cve-2026-59800-decolua-9router-os-command-injection-in-tailscale-install  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07. Updated: 2026-07-07  
License: CC BY 4.0 with a link back

CVE-2026-59800 · Severity: critical · CVSS 9.8 · Published 2026-07-07

9Router, a networking and routing tool, contains a critical security flaw in its Tailscale installation component. An unauthenticated attacker can remotely send a specially crafted request to the device to execute arbitrary system commands. This could lead to a complete takeover of the router, allowing attackers to intercept network traffic, access sensitive data, or use the device as a foothold for further attacks.

Technologies: [9router (npm)](https://junglewise.ai/threats/technologies/9router). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-59800 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-59800 being exploited in the wild.

**How severe is CVE-2026-59800?** Critical severity, with a CVSS score of 9.8, published 7 July 2026.

**Which products and versions are affected?** 9router (npm) SEMVER:introduced=0,fixed=0.4.44.

**Is there a fix for CVE-2026-59800?** Yes. 9router (npm): upgrade to 0.4.44 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-59800 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-59800?** Check whether you run 9router (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- 9router (npm): upgrade to 0.4.44 or later

  ```sh
  npm install 9router@0.4.44
  ```


## Technical details

An OS command injection vulnerability exists in 9Router versions prior to 0.4.44 due to improper input validation and missing authorization. The 'POST /api/tunnel/tailscale-install' endpoint is excluded from the dashboard middleware's authorization checks, allowing unauthenticated access. The application takes the 'sudoPassword' field from the request body and pipes it directly into the stdin of a 'sudo -S sh' process. In environments where the process runs as root (such as default Docker configurations) or where NOPASSWD is configured, the shell interprets the 'sudoPassword' value as a command rather than a password. Attackers can exploit this to achieve Remote Code Execution (RCE) with the privileges of the 9Router process. A patch is available in version 0.4.44.

## Affected products

- decolua 9router < 0.4.44

## Identifiers

- CVE-2026-59800
- GHSA-g6g7-pvmx-m74p

## Timeline

- 2026-05-29: advisory: Vendor published GHSA advisory
- 2026-07-04: exploited: First exploitation evidence observed by Shadowserver Foundation
- 2026-07-07: disclosed: CVE published to NVD

## References

- [https://github.com/decolua/9router/security/advisories/GHSA-g6g7-pvmx-m74p](https://github.com/decolua/9router/security/advisories/GHSA-g6g7-pvmx-m74p)
- [https://www.vulncheck.com/advisories/9router-os-command-injection-via-sudopassword-parameter-in-tailscale-install-endpoint](https://www.vulncheck.com/advisories/9router-os-command-injection-via-sudopassword-parameter-in-tailscale-install-endpoint)

## Related threats

- [9Router has a Login Brute-Force Lockout Bypass via Spoofable X-9r-Real-Ip Header](https://junglewise.ai/threats/cve-2026-56682-9router-login-brute-force-lockout-bypass-via-spoofable-header)
- [9Router has an Authentication Bypass in Public LLM API via Spoofable X-9r-Real-Ip Header](https://junglewise.ai/threats/cve-2026-56681-9router-authentication-bypass-in-public-llm-api-via-spoofable-x)
- [9Router unauthenticated server-side request forgery in OIDC test endpoint](https://junglewise.ai/threats/cve-2026-56677-9router-unauthenticated-server-side-request-forgery-in-oidc-test)
- [decolua 9Router mass assignment in /api/settings](https://junglewise.ai/threats/cve-2026-56679-decolua-9router-mass-assignment-in-api-settings)
- [decolua 9router SSRF and credential forwarding in Kiro API validation](https://junglewise.ai/threats/cve-2026-56678-decolua-9router-ssrf-and-credential-forwarding-in-kiro-api)