Vulnerability Description
OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response from a malicious proxy server
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openvpn | Openvpn | >= 2.1.0, < 2.6.21 |
Related Weaknesses (CWE)
References
- https://community.openvpn.net/ReleaseHistory#openvpn-2621-released-1-july-2026Release Notes
- https://community.openvpn.net/ReleaseHistory#openvpn-275-released-1-july-2026Release Notes
- https://community.openvpn.net/Security%20Announcements/CVE-2026-11771Vendor Advisory
FAQ
What is CVE-2026-11771?
CVE-2026-11771 is a vulnerability with a CVSS score of 7.5 (HIGH). OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM respo...
How severe is CVE-2026-11771?
CVE-2026-11771 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-11771?
Check the references section above for vendor advisories and patch information. Affected products include: Openvpn Openvpn.