CVE-2026-11604: openvpn ovpn-dco-win Heap-based Buffer Overflow
CVSS: 6.5v3.1MediumAnalyzed
Published 10-06-2026Last modified 11-06-2026
Vulnerability summary
CVE-2026-11604 is a medium (CVSS 6.5) Heap-based Buffer Overflow vulnerability in openvpn ovpn-dco-win. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities.
CVSS score
6.5/10
010
Medium · v3.1 (NVD)EPSS score
0.34%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-06-2026PublishedVulnerability first disclosed.
- 11-06-2026Last modifiedVulnerability information updated.
Description
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).
CVSS metrics
3 scores · 2 sources · 2 versionsMedium 5.6Preferred score · CVE.org (CNA)
CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:HSourcesAll 2 agree
- NVDNIST5.6MediumCVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Medium 6.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HSourcesSingle source
EPSS trend
Probability
0.34%
Chance of exploitation in the next 30 days
Percentile
26%
Versus all other CVEs
30-day change
0.00 pp
From 0.34% on 20-09-2026
20-09-202620-10-2026
EPSS score0.34%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
- CWE-131Incorrect Calculation of Buffer SizeThe product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Openvpn1 product
- ovpn-dco-win≥ 2.0.0, ≤ 2.5.8 | ≥ 2.0.0, ≤ 2.8.3
1 vendor · 1 product