OpenVPN 2.7_alpha1 through 2.7.7 allows remote authenticated users to impersonate others via a crafted certificate subject field

published 2026-10-13 26 d ago modified 2026-10-18 21 d ago also EUVD-2026-100750

cvss: 7.6; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits: 0; none known

Patch / fix

distros 2

debian ubuntu

openvpn Debian 14 2.7.8-1

debian advisories DEBIAN-CVE-2026-84790

openvpn Ubuntu 22.04 LTS 2.5.11-0ubuntu0.22.04.6
openvpn Ubuntu 24.04 LTS 2.6.19-0ubuntu0.24.04.5
openvpn Ubuntu 26.10 2.7.7-1ubuntu1.1
openvpn Ubuntu 26.04 LTS 2.7.0-1ubuntu1.4

ubuntu advisories UBUNTU-CVE-2026-84790

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-84790 updated 2026-10-15 cvss 6.8

openvpn: OpenVPN: User impersonation via crafted certificate subject field

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 21 d ago (2026-10-18)

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.6	CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA	4.0	7.6	CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

OpenVPN OpenVPN

Classification

Weakness

CWE-290 Authentication Bypass by Spoofing
CWE-158 Improper Neutralization of Null Byte or NUL Character

References

community.openvpn.net /Security%20Announcements/CVE-2026-84790
vendor-advisory

Sources

CVE List CVE-2026-84790
NVD CVE-2026-84790

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary