# 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](https://www.cve.org/CVERecord?id=CVE-2026-11604)

Release notes:
* [ovpn-dco-win-2.8.3](https://github.com/OpenVPN/ovpn-dco-win/releases/tag/2.8.3)