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TI-2026-10158 Aliases CVE-2026-11771GHSA-v8ww-fhqp-9vff

Stack-based buffer overflow in OpenVPN

Priority LOW 31CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
High
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00375 31st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OpenVPNOpenVPN2.1.0 – 2.6.20; 2.7_alpha1 – 2.7.4—No fix listedCNA
  • OpenVPN VendorOpenVPN Affected 2.1.0 – 2.6.20; 2.7_alpha1 – 2.7.4 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openvpn:openvpn:*:*:*:*:*:*:*:*2.1.0 to before 2.6.21; 2.7 to before 2.7.5VulnerableOpenVPN
  • cpe:2.3:a:openvpn:openvpn:*:*:*:*:*:*:*:* Versions 2.1.0 to before 2.6.21; 2.7 to before 2.7.5 Vulnerable ·OpenVPN

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-11771
  2. 2026-10-03 Alias added: GHSA-v8ww-fhqp-9vff
  3. 2026-10-23 EPSS moved to the below the 50th percentile

References

Advisory 1

Other 2

  • TI-2014-04453 Unquoted Windows search path vulnerability in the ptservice service prior to… CVSS 3.1MEDIUM 5.3
  • TI-2022-00467 Authentication bypass in OpenVPN CVSS 3.1CRITICAL 9.8
  • TI-2024-18509 Unrestricted file upload in OpenVPN 2 CVSS 3.1CRITICAL 9.8
  • TI-2024-16468 The interactive service in OpenVPN 2.6.9 and earlier allows the OpenVPN service pipe to… CVSS 3.1HIGH 7.5
  • TI-2023-25309 Use after free in OpenVPN 2 CVSS 3.1CRITICAL 9.8
  • TI-2024-05196 OpenVPN before 2.6.11 does not santize PUSH_REPLY messages properly which an attacker… CVSS 3.1CRITICAL 9.1
See all 48 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences