Buffer overflow in Openvpn
CVE-2026-11604
An incorrect buffer size calculation in the epoch key generator in OpenVPN ovpn-dco-win version 2.0.0 through 2.8.3 allows a remote authenticated peer to trigger a heap-based buffer overflow and kernel memory corruption via a crafted data packet, resulting in a system crash (denial of service).
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (24.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Openvpn
- Openvpn Ovpn-Dco-Win — versions 2.0.0
Weakness classification (CWE)
References
- community.openvpn.net/Security Announcements/CVE-2026-11604 (vendor-advisory, Vendor Advisory)
- github.com/OpenVPN/ovpn-dco-win/releases (product, Release Notes)
Frequently asked questions
- What is CVE-2026-11604?
- CVE-2026-11604 is a medium-severity vulnerability in Openvpn, classified under Heap-based Buffer Overflow. CVSS score: 6.5/10. Published 2026-06-10.
- How severe is CVE-2026-11604?
- Medium severity. CVSS v3 base score is 6.5 out of 10.