Vulnerability · Published Sep 7, 2026 · Assigned by OpenVPN
CVE-2026-78221
Medium 5.9
In plain English
A medium-severity security flaw in OpenVPN from OpenVPN. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).
Severity (CVSS 4.0)5.9Medium
Exploit odds (30 days)0.1%top 98.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An incorrect buffer size calculation in the Windows Interactive Service in OpenVPN 2.7_alpha1 through 2.7.6 allows local authenticated users to cause memory corruption or disclose sensitive information via crafted NRPT inputs.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | openvpn | no fix listed | UBUNTU-CVE-2026-78221 |
| Ubuntu:24.04:LTS | openvpn | no fix listed | UBUNTU-CVE-2026-78221 |
| Ubuntu:26.04:LTS | openvpn | no fix listed | UBUNTU-CVE-2026-78221 |
Affected products (as reported)
Weakness: CWE-131 · Vector: CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:H/VI:N/VA:H/SC:H/SI:N/SA:H