CVE-2026-12996

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to denial-of-service and/or possibly sensitive memory leak triggered by man-in-the-middle attacker.

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to remote denial-of-service when receiving malformed IPv6 packet.

OpenVPN version 2.3.12 and newer is vulnerable to unauthenticated Denial of Service of server via received large control packet. This issue is fixed in 2.3.15 and 2.4.2.

The Windows interactive service in OpenVPN (versions 2.7_alpha1 through 2.7.4) allows remote attackers to cause persistent DNS state pollution or a service crash via a crafted search domain during disconnection.

Insufficient argument validation in OpenVPN 2.7_alpha1 through 2.7_rc1 allows an attacker to trigger a heap buffer over-read when parsing IP addresses.

OpenVPN versions 2.6.0 to 2.6.6 contain a use after free vulnerability that may lead to undefined behavior, leaking memory buffers, or remote code execution when sending network buffers to a remote peer.

OpenVPN versions before 2.3.3 and 2.4.x before 2.4.4 are vulnerable to a buffer overflow vulnerability when key-method 1 is used, possibly resulting in code execution.

OpenVPN 2.7_alpha1 through 2.7.5 using mbedTLS allows remote authenticated users to be misidentified by ignoring the configured X.509 username identity lookup field.

The Windows interactive service in OpenVPN 2.4.0 through 2.6.21 and 2.7_alpha1 through 2.7.5 allows local authenticated users to bypass the trusted configuration directory constraint and load arbitrary configuration files via crafted options that bypass whitelist checks.

In OpenVPN (versions 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4), an incomplete guard allows remote authenticated peers to trigger a use-after-free during TLS session promotion, potentially leading to denial of service or memory leakage.