Read the docs
TI-2026-56385 Aliases CVE-2026-81738GHSA-7xfh-h474-9hf7

Stack-based buffer overflow in OpenVPN

Priority LOW 12CWE-121Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

OpenVPN 2.5.0 through 2.7.6 on Windows using the tap-windows6 driver allows attackers to trigger an out-of-bounds write via crafted DOMAIN-SEARCH entries

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00331 26th 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
OpenVPNOpenVPN2.5.0 – 2.7.6—No fix listedCNA
  • OpenVPN VendorOpenVPN Affected 2.5.0 – 2.7.6 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:openvpn:openvpn:*:*:*:*:*:*:*:*——OpenVPN
  • cpe:2.3:a:openvpn:openvpn:*:*:*:*:*:*:*:* Versions — — ·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-2026-81738
  2. 2026-10-03 Alias added: GHSA-7xfh-h474-9hf7

References

Advisory 1

  • TI-2024-01215 Integer overflow in OpenVPN tap-windows6 CVSS 3.1CRITICAL 9.8
  • 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
See all 99 →

Sources

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