What’s Vulnerable › Vulnerabilities

CVE-2021-3547

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-12 · updated 2026-06-17
• Weakness: CWE-305

Description

OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.

Affected products

• OpenVPN: 3.6, 3.6.1

References

• https://community.openvpn.net/openvpn/wiki/CVE-2021-3547
• https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements
• https://community.openvpn.net/openvpn/wiki/CVE-2021-3547
• https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements

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