CVE-2026-11771

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://community.openvpn.net/ReleaseHistory#openvpn-2621-released-1-july-2026	Release Notes
https://community.openvpn.net/ReleaseHistory#openvpn-275-released-1-july-2026	Release Notes
https://community.openvpn.net/Security%20Announcements/CVE-2026-11771	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:openvpn:openvpn::::::::
	cpe:2.3:a:openvpn:openvpn::::::::

History

No history.

Information

Published : 2026-07-30 17:16

Updated : 2026-08-05 19:38

NVD link : CVE-2026-11771

Mitre link : CVE-2026-11771

CVE.ORG link : CVE-2026-11771

JSON object : View

Products Affected

openvpn

openvpn

CWE

CWE-121

Stack-based Buffer Overflow

CWE-193

Off-by-one Error

CWE-787

Out-of-bounds Write

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