CVE-2026-91838: Gnome Networkmanager-Sstp

High severity, CVSS 7.8. EPSS: 0.1% chance of exploitation in the next 30 days.

A flaw was found in NetworkManager-sstp, the SSTP VPN plugin for NetworkManager. A local unprivileged user can exploit this vulnerability by embedding special characters, known as shell metacharacters, into VPN connection profile fields such as CA certificate or proxy settings. These unescaped characters are then processed by the `pppd` daemon, which runs with root privileges, allowing the attacker to execute arbitrary commands with elevated permissions when a malicious VPN connection is activated.

Affected products

• Gnome Networkmanager-Sstp: any version

Published 2026-09-25. Last modified 2026-09-30.