Memory leak in OpenVPN Server - CVE-2026-12932

Vulnerability identifier: #VU139873

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-12932

CWE-ID: CWE-401

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a memory leak in tls-crypt-v2 client key handling when processing tls-crypt-v2 client keys. A remote attacker can send a sequence of crafted inputs to cause a denial of service.

The issue can lead to an out-of-memory condition before the server crashes.

OpenVPN Server
Debian Linux
openSUSE Leap
Ubuntu
openEuler
openvpn-down-root-plugin-debuginfo
openvpn-devel
openvpn-debuginfo
openvpn-auth-pam-plugin-debuginfo
openvpn
openvpn-debugsource
openvpn-down-root-plugin
openvpn-auth-pam-plugin
openvpn (Ubuntu package)
openvpn-help
openvpn (Debian package)

Install security update from vendor's website.

OpenVPN Server - addressed in versions 2.6.21, 2.7.5
openvpn-down-root-plugin-debuginfo - update to 2.5.6-150400.3.12.1
openvpn-devel - update to 2.5.6-150400.3.12.1
openvpn-debuginfo - update to 2.5.6-150400.3.12.1
openvpn-auth-pam-plugin-debuginfo - update to 2.5.6-150400.3.12.1
openvpn - update to 2.5.6-150400.3.12.1
openvpn-debugsource - update to 2.5.6-150400.3.12.1
openvpn-down-root-plugin - update to 2.5.6-150400.3.12.1
openvpn-auth-pam-plugin - update to 2.5.6-150400.3.12.1
openvpn (Ubuntu package) - addressed in versions 2.5.11-0ubuntu0.22.04.4, 2.6.19-0ubuntu0.24.04.3, 2.7.0-1ubuntu1.2
openvpn-debugsource - update to 2.6.9-8
openvpn-help - update to 2.6.9-8
openvpn-devel - update to 2.6.9-8
openvpn-debuginfo - update to 2.6.9-8
openvpn - update to 2.6.9-8
openvpn (Debian package) - update to 2.6.14-1+deb13u3

• https://github.com/OpenVPN/openvpn/releases/tag/v2.6.21
• https://github.com/OpenVPN/openvpn/commit/4dee614e4e799d6d4a20bffabd902291c86406f2

• Multiple vulnerabilities in OpenVPN Server
• Debian update for openvpn
• openEuler 24.03 LTS SP1 update for openvpn
• openEuler 24.03 LTS SP3 update for openvpn
• openEuler 24.03 LTS SP4 update for openvpn
• Ubuntu update for openvpn
• SUSE update for openvpn