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 v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-2738
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: OpenVPN
Affected software:
OpenVPN Data Channel Offload driver for Windows
OpenVPN Data Channel Offload driver for Windows
Detailed vulnerability description
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.
How to mitigate CVE-2026-2738
Install security update from vendor's website.