Executive brief
OpenVPN, a widely used software for creating secure private networks, contains a vulnerability that could allow an authenticated user to crash the VPN server. By exploiting a flaw in how the software manages memory during secure connection handovers, a remote attacker could cause a service outage or potentially leak sensitive information from the server's memory. This could disrupt business operations and remote access for all users connected to the affected server.
Technical details
A use-after-free (UAF) vulnerability exists in OpenVPN versions 2.6.0-2.6.20 and 2.7_alpha1-2.7.4 due to an incomplete guard during TLS session promotion. An authenticated remote peer can exploit this flaw by sending specifically crafted sequences during the session promotion phase. Successful exploitation can lead to a crash of the OpenVPN process (Denial of Service) or the leakage of sensitive memory contents. The vulnerability is tracked as CWE-416 and has been addressed in OpenVPN versions 2.6.21 and 2.7.5.
Affected products
- OpenVPN Inc. OpenVPN 2.6.0 through 2.6.20, 2.7_alpha1 through 2.7.4
Timeline
- 2026-07-01: patched: Fixed in versions 2.6.21 and 2.7.5
- 2026-07-30: disclosed: CVE-2026-13117 published