Networkmanager-vpnc: networkmanager-vpnc: local privilege escalation to root via newline injection in vpn username
Summary
| CVE | CVE-2026-91840 |
|---|---|
| State | PUBLISHED |
| Assigner | fedora |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 18:17:32 UTC |
| Updated | 2026-09-30 19:57:08 UTC |
| Description | 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. |
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: 0.001930000 probability, percentile 0.080940000 (date 2026-10-01)
Problem Types: CWE-93 | CWE-93 Improper Neutralization of CRLF Sequences ('CRLF 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-vpnc | affected * semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-91840 | [email protected] | access.redhat.com | |
| gitlab.gnome.org/Archive/NetworkManager-vpnc/-/work_items/19 | [email protected] | gitlab.gnome.org | |
| 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 | 2026-09-15T09:50:37.313Z | Reported to Red Hat. |
| CNA | 2026-09-15T09:50:37.313Z | Made public. |
Workarounds
CNA: If vpnc VPN connections are not required, the NetworkManager-vpnc package can be removed to eliminate the vulnerability. This action will prevent the system from establishing vpnc-based VPN connections. To remove the package, execute the following command as root: `# dnf remove NetworkManager-vpnc` Note that removing this package may impact functionality if vpnc VPNs are actively used.