OpenVPN up to 2.6.22/2.7.6 Certificate Parsing certificate validation

Summaryinfo

A vulnerability described as problematic has been identified in OpenVPN up to 2.6.22/2.7.6. The impacted element is an unknown function of the component Certificate Parsing. The manipulation results in certificate validation. This vulnerability is identified as CVE-2026-84256. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in OpenVPN up to 2.6.22/2.7.6. It has been classified as problematic. Affected is an unknown code block of the component Certificate Parsing. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on integrity. CVE summarizes:

An argument parsing issue in OpenVPN 2.1_rc10 through 2.6.22 and 2.7_alpha1 through 2.7.6 on Windows allows remote authenticated users to execute arbitrary commands via a crafted certificate subject

The advisory is shared for download at community.openvpn.net. This vulnerability is traded as CVE-2026-84256 since 09/01/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/07/2026). The MITRE ATT&CK project declares the attack technique as T1587.003.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Network Encryption Software

Name

• OpenVPN

Version

• 2.6.0
• 2.6.1
• 2.6.2
• 2.6.3
• 2.6.4
• 2.6.5
• 2.6.6
• 2.6.7
• 2.6.8
• 2.6.9
• 2.6.10
• 2.6.11
• 2.6.12
• 2.6.13
• 2.6.14
• 2.6.15
• 2.6.16
• 2.6.17
• 2.6.18
• 2.6.19
• 2.6.20
• 2.6.21
• 2.6.22
• 2.7.0
• 2.7.1
• 2.7.2
• 2.7.3
• 2.7.4
• 2.7.5
• 2.7.6

License

• open-source

CPE 2.3info

• 🔒
• 🔒
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CPE 2.2info

• 🔒
• 🔒
• 🔒

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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