---
id: CVE-2026-91840
title: A flaw was found in NetworkManager-vpnc
summary: >-
  A flaw was found in NetworkManager-vpnc. This vulnerability allows a local
  unprivileged user to escalate privileges to root. By injecting a newline
  character into the VPN username field, an attacker can manipulate the vpnc
  configuration …
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-93
vendor: GNOME
product: network-manager-vpnc
affected:
  - network-manager-vpnc < *
published: '2026-09-25'
updated: '2026-09-26'
sourceUpdated: '2026-09-26T04:17:51.307'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91840'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91840'
    label: patrick@puiterwijk.org
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533642'
    label: patrick@puiterwijk.org
  - url: 'https://gitlab.gnome.org/Archive/NetworkManager-vpnc/-/work_items/19'
    label: patrick@puiterwijk.org
  - url: 'https://gitlab.gnome.org/Archive/NetworkManager-vpnc/-/work_items/19'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91840.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91840'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-25T18:14:55.161832Z'
exploitAvailable: true
ingestedAt: '2026-09-25T18:14:20.401Z'
---

## Overview

A flaw was found in NetworkManager-vpnc. This vulnerability allows a local unprivileged user to escalate privileges to root. By injecting a newline character into the VPN username field, an attacker can manipulate the vpnc configuration to execute an arbitrary program with root privileges when the malicious VPN connection is activated.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91840.json)