PT-2026-57584 · Openvpn · Openvpn

CVE-2026-11771 · Published 2026-07-02 · Updated 2026-07-30

Positive Technologies (AI Summary)

CVSS v4.0

7.0

High

Base vector

AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

Name of the Vulnerable Software and Affected Versions OpenVPN versions 2.1.0 through 2.6.20 OpenVPN versions 2.7 alpha1 through 2.7.4

Description An off-by-one buffer write occurs during NTLM proxy authentication. This 1-byte buffer overrun can be triggered by a malicious proxy server sending a crafted NTLM response, potentially leading to a system crash.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Memory Corruption

Stack Overflow

Weakness Enumeration

CWE-193

CWE-787

CWE-121

Related Identifiers

CVE-2026-11771

OESA-2026-2917

OESA-2026-2918

OESA-2026-3001

USN-8540-1

Affected Products

Openvpn

References · 27

• https://cve.org/CVERecord?id=CVE-2026-11771 · Security Note
• https://community.openvpn.net/Security%20Announcements/CVE-2026-11771 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-12932 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2026-2917 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-12996 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-11771 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-11771 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-12996 · Vendor Advisory
• https://osv.dev/vulnerability/USN-8540-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-13122 · Security Note
• https://ubuntu.com/security/CVE-2026-13117 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-8540-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-13117 · Security Note
• https://osv.dev/vulnerability/OESA-2026-3001 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-13698 · Vendor Advisory