What is CVE-2026-91838?

CVE-2026-91838 is a high-severity vulnerability in GNOME Networkmanager-Sstp, classified under OS Command Injection. CVSS score: 7.8/10. Published 2026-09-25.

How severe is CVE-2026-91838?

High severity. CVSS v3 base score is 7.8 out of 10.

RCE in GNOME Networkmanager-Sstp

CVE-2026-91838

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.

Vulnerability class: Command Injection (OS Command Injection)

Published 2026-09-25 · last modified 2026-09-25.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

GNOME Networkmanager-Sstp

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

access.redhat.com/security/cve/CVE-2026-91838 (vdb-entry)
bugzilla.redhat.com/show_bug.cgi (issue-tracking)
gitlab.gnome.org/GNOME/network-manager-sstp/-/work_items/67

Frequently asked questions

What is CVE-2026-91838?: CVE-2026-91838 is a high-severity vulnerability in GNOME Networkmanager-Sstp, classified under OS Command Injection. CVSS score: 7.8/10. Published 2026-09-25.
How severe is CVE-2026-91838?: High severity. CVSS v3 base score is 7.8 out of 10.