OpenVPN/openvpn v2.6.22 on GitHub

openvpnserv (windows): better scrutinize command line passed in
from the control socket to openvpn. This would lead to circumventing
admin restrictions on allowed openvpn config directories (but never
to "read files the user has no permissions for") (CVE-2026-63649)
Bug found by 章鱼哥 (www.aipyaipy.com)
dco: make key state desync recoverable
This was reported as a "with suitable timing, a key-update de-sync between
OpenVPN and the kernel could trigger an ASSERT()", and was initially
handled as security report. It turned out to be not exploitable, but the
state machine was not very robust and so the opportunity was used to
improve the code.
Bug found by 章鱼哥 (www.aipyaipy.com)

refuse incoming HARD RESET packets with a sequence ID != 0
(this is basically making an OpenVPN server ignore and log a
"should never happen" client-side misbehaviour, which could lead to
TLS handshake establishment failures in p2p TLS setups)
correct minimum packet length check for 802.1q tagged packets
(Github: OpenVPN/openvpn#1044).
This was also reported (twice) as a security bug, as technically
OpenVPN with --client-nat would read and write up to 4 bytes
"after the end of the packet" - but due to the OpenVPN packet buffer
layouts, which are always full-frame-sized this is fully safe and has
no adverse consequences.

Full Changelog: v2.6.21...v2.6.22