CVE-2026-79766: Termix: OS command injection in ACME/Let's Encrypt certificate-request handler via admin-controlled domain/email
Termix is a web-based server management platform with SSH terminal, tunneling, and file editing capabilities. From 2.4.1 until 2.5.1, an authenticated Termix administrator can store attacker-controlled domain and email values through PATCH /users/acme-ssl-settings and trigger their interpolation into a certbot shell command through POST /users/acme-ssl-request. In src/backend/database/routes/acme-ssl-routes.ts, childprocess.execSync invokes /bin/sh -c with those values only wrapped in double quotes, so shell metacharacters can execute arbitrary operating-system commands as the Termix backend process. Both HTTP webroot and DNS Cloudflare challenge modes are affected, and compromise exposes Termix databases, process secrets, stored credentials, and network reachability. This issue is fixed in version 2.5.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Termixto a version that resolves this vulnerability.Fixed in 2.5.1
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated Termix administrator can exploit it. The attacker must be able to update ACME SSL settings through PATCH /users/acme-ssl-settings and then submit a certificate request through POST /users/acme-ssl-request.
Are both ACME validation methods affected?
Yes. The HTTP webroot and DNS Cloudflare challenge modes are both affected because attacker-controlled domain and email values are interpolated into the certbot shell command.
What is the impact of successful exploitation?
Commands execute with the privileges of the Termix backend process. This can expose Termix databases, process secrets, stored credentials, and systems reachable from the affected host.
Which versions need remediation?
Termix versions from 2.4.1 until 2.5.1 are affected. The issue is fixed in version 2.5.1.