openvpn vulnerabilities

CVE-2026-106017

Improper certificate validation in the OpenVPN 3 Core library version 3.4 through 3.11.7 allows attackers to circumvent extended key usage restrictions.

CVE-2026-84471

The fix for CVE-2026-12996 was incomplete. A use-after-free in OpenVPN 2.6.0 through 2.6.22 and 2.7_alpha1 through 2.7.7 allows remote authenticated peers to potentially cause a denial of service or leak memory via crafted packets during TLS session promotion or expiry.

• Update to 2.6.19-0ubuntu0.24.04.4

CVE-2026-84790

OpenVPN 2.7_alpha1 through 2.7.7 allows remote authenticated users to impersonate others via a crafted certificate subject field

• Update to 2.6.19-0ubuntu0.24.04.5

CVE-2026-84732

Retransmissions of ACK packet ID in OpenVPN through 2.6.22 and 2.7.6 allow remote unauthenticated attackers to cause a denial of service via crafted inputs that trigger a timeout integer overflow

• Update to 2.6.19-0ubuntu0.24.04.4

CVE-2026-12932

A memory leak in the tls-crypt-v2 client key extraction in OpenVPN 2.5.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote attackers to cause a denial of service (memory exhaustion) via a flood of crafted packets

• Update to 2.6.19-0ubuntu0.24.04.3

CVE-2026-12996

A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote authenticated peers to potentially cause a denial of service or leak memory via crafted packets during TLS session promotion or expiry

• Update to 2.6.19-0ubuntu0.24.04.3

CVE-2026-11771

OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response from a malicious proxy server

• Update to 2.6.19-0ubuntu0.24.04.3

CVE-2026-13117

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

• Update to 2.6.19-0ubuntu0.24.04.3

CVE-2026-13122

OpenVPN version 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote attackers to cause a denial of service via a malformed authentication token that triggers a reachable assertion when external-auth is enabled

• Update to 2.6.19-0ubuntu0.24.04.3

CVE-2026-13698

A memory leak in OpenVPN version 2.5.0 through 2.5.11, 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote attackers with a valid tls-crypt-v2 client key to potentially cause a denial of service

• Update to 2.6.19-0ubuntu0.24.04.3

CVE-2026-40215

A race condition in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows remote attackers to potentially cause a server crash or leak heap memory via a use-after-free triggered during TLS session promotion.

• Update to 2.6.19-0ubuntu0.24.04.2

CVE-2026-35058

Improper validation of packet length during tls-crypt-v2 key extraction in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows authenticated attackers to trigger a fatal assertion and cause a denial of service via a specially crafted packet.

• Update to 2.6.19-0ubuntu0.24.04.2

CVE-2025-13086

Improper validation of source IP addresses in OpenVPN version 2.6.0 through 2.6.15 and 2.7_alpha1 through 2.7_rc1 allows an attacker to open a session from a different IP address which did not initiate the connection resulting in a denial of service for the originating client

• Update to 2.6.14-0ubuntu0.24.04.3

CVE-2025-2704

OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger a denial of service by corrupting and replaying network packets in the early handshake phase

• Update to 2.6.12-0ubuntu0.24.04.3

CVE-2024-5594

OpenVPN before 2.6.11 does not santize PUSH_REPLY messages properly which an attacker controlling the server can use to inject unexpected arbitrary data ending up in client logs.

• Update to 2.6.9-1ubuntu4.1

CVE-2024-28882

OpenVPN from 2.6.0 through 2.6.10 in a server role accepts multiple exit notifications from authenticated clients which will extend the validity of a closing session

• Update to 2.6.9-1ubuntu4.1

DHCP routing options can manipulate interface-based VPN traffic

DHCP can add routes to a client’s routing table via the classless static route option (121). VPN-based security solutions that rely on routes to redirect traffic can be forced to leak traffic over the physical interface. An attacker on the same local network can read, disrupt, or possibly modify network traffic that was expected to be protected by the VPN.

CVE-2020-20813

Control Channel in OpenVPN 2.4.7 and earlier allows remote attackers to cause a denial of service via crafted reset packet.