CVE-2026-84471 - Possible double-free in check_session_buf_not_used() lame duck handling

OpenVPN 2.x allows attackers to potentially cause a double-free of a TLS session buffer in the lame duck case, because the guard in check_session_buf_not_used() was incomplete. This extends the earlier fix for CVE-2026-13117.

OpenVPN version 2.6.0 through 2.6.22 and 2.7_alpha1 through 2.7.6 are affected. This is fixed in versions 2.6.23 and 2.7.7.