Networkmanager-sstp: networkmanager-sstp: local privilege escalation to root via shell injection in vpn profile fields
Summary
| CVE | CVE-2026-91838 |
|---|---|
| State | PUBLISHED |
| Assigner | fedora |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 18:17:32 UTC |
| Updated | 2026-09-25 19:17:58 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001000000 probability, percentile 0.008170000 (date 2026-09-26)
Problem Types: CWE-78 | CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | GNOME | NetworkManager-sstp | affected * semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| gitlab.gnome.org/GNOME/network-manager-sstp/-/work_items/67 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | gitlab.gnome.org | |
| access.redhat.com/security/cve/CVE-2026-91838 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Andreas Gabriel Berbescu for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-09-15T09:39:06.004Z | Reported to Red Hat. |
| CNA | 2026-09-15T09:39:06.004Z | Made public. |
Workarounds
CNA: The vulnerability requires a local unprivileged user to activate a malicious VPN connection. If the NetworkManager-sstp package is not required, removing it will eliminate the attack vector. To remove the `NetworkManager-sstp` package: `sudo dnf remove NetworkManager-sstp` This action may impact functionality that relies on SSTP VPN connections.