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

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-3226 advisory.

    When using the OpenSSL library, we escaped embedded null-bytes in a certificate's subject in     x509_get_subject(), but in extract_x509_field_ssl(), we copied any null-bytes that are contained in the     field value. When using the option --verify-x509-name, this could lead to an incorrect name being     accepted. For example, the common name admin\0impersonator would be accepted when running with
    --verify-x509-name admin name.

    Fixed by: https://github.com/OpenVPN/openvpn/commit/cf4384eef4676a01bd3ee98fa602f7b2af8079ea (v2.7.8)     (CVE-2026-84790)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 host has a package installed that is affected by a vulnerability as referenced in the USN-8953-1 advisory.

    It was discovered that OpenVPN incorrectly handled certificate subject fields. A remote authenticated user     could possibly use this issue to impersonate other users.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - OpenVPN 2.7_alpha1 through 2.7.7 allows remote authenticated users to impersonate others via a crafted     certificate subject field (CVE-2026-84790)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
371861	Amazon Linux 2023 : openvpn, openvpn-devel (ALAS2023-2026-3226)	Nessus	Amazon Linux Local Security Checks	Local	high
371125	Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS / 26.10 : OpenVPN vulnerability (USN-8953-1)	Nessus	Ubuntu Local Security Checks	Local	high
364132	Linux Distros Unpatched Vulnerability : CVE-2026-84790	Nessus	Misc.	Local	high

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