OpenVPN 2.7_alpha1-2.7.6: Buf Size Defect in WIntSrv (CVE-2026-78221)
CVE-2026-78221 Published on September 7, 2026

An incorrect buffer size calculation in the Windows Interactive Service in OpenVPN 2.7_alpha1 through 2.7.6 allows local authenticated users to cause memory corruption or disclose sensitive information via crafted NRPT inputs.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-78221 can be exploited with local system access. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.

Attack Vector:
LOCAL
Attack Complexity:
HIGH
Privileges Required:
LOW
User Interaction:
PASSIVE

Weakness Type

Incorrect Calculation of Buffer Size

The software does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.


Products Associated with CVE-2026-78221

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Affected Versions

OpenVPN: