OpenVPN up to 2.6.20/2.7.4 TLS Session Promotion use after free

Summaryinfo

A vulnerability was found in OpenVPN up to 2.6.20/2.7.4. It has been classified as very critical. This affects an unknown function of the component TLS Session Promotion. This manipulation causes use after free. This vulnerability is registered as CVE-2026-13117. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in OpenVPN up to 2.6.20/2.7.4. It has been declared as very critical. Affected by this vulnerability is an unknown code block of the component TLS Session Promotion. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

An incomplete guard in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote authenticated peers to trigger a use-after-free during TLS session promotion, potentially leading to a denial of service or memory leakage

The advisory is shared at community.openvpn.net. This vulnerability is known as CVE-2026-13117 since 06/23/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/30/2026).

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

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-51234). Several companies clearly confirm that VulDB is the primary source for best 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
• 2.7.0
• 2.7.1
• 2.7.2
• 2.7.3
• 2.7.4

License

• open-source

CPE 2.3info

• 🔒
• 🔒
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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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