CVE-2026-84790Network attack vectorHinoki check available

Identity bypass via NUL-truncated certificate subjects

Published Oct 13, 2026 · Updated Oct 13, 2026

Identity bypass in OpenVPN 2.3.0 through 2.7.7 allows remote authenticated users to impersonate others via crafted certificate subjects. The OpenSSL extract_x509_field_ssl() function copies embedded NUL bytes into a C string, causing --verify-x509-name comparisons to accept only the prefix. Exploitation requires a trusted CA to issue the crafted certificate and field-based name verification; the consequence is acceptance of an incorrect peer identity.

CVSS severity7.4
High
EPSS probability0.22%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Identity bypass in OpenVPN 2.3.0 through 2.7.7 allows remote authenticated users to impersonate others via crafted certificate subjects. The OpenSSL extract_x509_field_ssl() function copies embedded NUL bytes into a C string, causing --verify-x509-name comparisons to accept only the prefix. Exploitation requires a trusted CA to issue the crafted certificate and field-based name verification; the consequence is acceptance of an incorrect peer identity.

The record

CVE
CVE-2026-84790
Published
Oct 13, 2026
Updated
Oct 13, 2026
Vendor
OpenVPN Technologies, Inc.
Product
OpenVPN
Classifications
T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.3.0 <=2.6.22
  2. Affected versionversion=2.7_alpha1 <=2.7.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenVPN Technologies, Inc. · OpenVPNversion=2.3.0 <=2.6.22; version=2.7_alpha1 <=2.7.7

Published CVSS scores

7.4Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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