CVE-2026-78221 json
An incorrect buffer size calculation in the Windows Interactive Service in OpenVPN 2.7_alpha1 through 2.7.6 allows local authenticated user…
published 2026-09-07 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-72276
- cvss
- 5.9
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 1%
- public exploits
- 0
- none known
Summary
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.
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-78221 updated cvss 7.5
OpenVPN: OpenVPN: Memory corruption and information disclosure vulnerability
-
Red Hat All currently supported Red Hat productsnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.9 | 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 |
| CNA | 4.0 | 5.9 | 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/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 |
Affected products
- OpenVPN OpenVPN
Classification
- Weakness
-
- CWE-131 Incorrect Calculation of Buffer Size
References
-
community.openvpn.net
/Security%20Announcements/CVE-2026-78221
vendor-advisory
Sources
- CVE List CVE-2026-78221
- NVD CVE-2026-78221
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.