CVE-2026-59800
9Router < 0.4.44 - OS Command Injection via sudoPassword Parameter in Tailscale Install Endpoint
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).
INFO
Published Date :
July 7, 2026, 7:16 p.m.
Last Modified :
July 7, 2026, 7:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-59800
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update 9Router to version 0.4.44 or later.
- Review sudo configurations for NOPASSWD.
- Restrict access to the /api/tunnel/tailscale-install endpoint.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-59800.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-59800 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-59800
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-59800 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-59800 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jul. 07, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/decolua/9router', 'vendor': 'decolua', 'product': '9router', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.4.44', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '0.4.44', 'versionType': 'semver'}], 'packageURL': 'pkg:npm/9router', 'defaultStatus': 'unaffected'}] Added 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). Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-78 Added Reference https://github.com/decolua/9router/security/advisories/GHSA-g6g7-pvmx-m74p Added Reference https://www.vulncheck.com/advisories/9router-os-command-injection-via-sudopassword-parameter-in-tailscale-install-endpoint