Bug 2533689

Summary: CVE-2026-91838 NetworkManager-sstp: NetworkManager-sstp: local privilege escalation to root via shell injection in VPN profile fields [fedora-all]
Product: [Fedora] Fedora Reporter: Vladimir Vasilev <vvasilev>
Component: NetworkManager-sstpAssignee: Marcin Zajaczkowski <mszpak>
Status: ASSIGNED --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: rawhideCC: lkundrak, mcatanza, mszpak
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["1cb8763d-48a3-4182-bfea-d869b44837b3"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2533637    

Description Vladimir Vasilev 2026-09-15 10:54:51 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A privilege escalation flaw was found in NetworkManager-sstp, the SSTP VPN plugin for NetworkManager. The construct_pppd_args() function in nm-sstp-service.c concatenates user-controlled connection profile fields, including ca-cert and proxy settings, into the pty argument passed to pppd without properly shell-escaping them. Because pppd invokes this pty command through /bin/sh -c while running as root, a local unprivileged user can embed shell metacharacters in these connection profile fields to have arbitrary commands executed with root privileges when the malicious VPN connection is activated.
Comment 1 Marcin Zajaczkowski 2026-09-15 17:52:25 UTC 
I asked in the upstream issue for a patch to apply: https://gitlab.gnome.org/GNOME/network-manager-sstp/-/issues/67 (I don't see any related changes in Git).