CVE-2026-11604 - Windows kernel heap corruption via max epoch fast-forward in receive-key generation
An incorrect buffer size calculation in the epoch key generator in OpenVPN ovpn-dco-win allows a remote authenticated peer to trigger a heap-based buffer overflow and kernel memory corruption via a crafted data packet, resulting in a system crash (denial of service).
ovpn-dco-win driver for Windows version 2.0.0 through 2.8.2 are affected. This is fixed in version 2.8.3.
A fixed driver is contained in OpenVPN Windows installer packages for 2.7.4-I002.
CVE Record: CVE-2026-11604
Release notes: