Heap-based buffer overflow in OpenVPN Data Channel Offload driver for Windows - CVE-2026-2738
Published: April 24, 2026
Vulnerability identifier: #VU127530
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-2738
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow in the ovpn-dco-win data channel offload driver when processing encrypted packets from a connected OpenVPN server with data epoch keys support. A remote user can send crafted encrypted packets to cause a denial of service.
The issue occurs when connecting to an OpenVPN 2.7.0 server or another implementation that supports data epoch keys.
Affected software
OpenVPN Data Channel Offload driver for Windows
How to mitigate CVE-2026-2738
Install security update from vendor's website.
OpenVPN Data Channel Offload driver for Windows - update to 2.8.2