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OpenvpnApplication

CVE-2026-13698

HIGH · 7.5 CVSS v3.1 Published 2026-07-06
Fix available
A fix is available. Upgrade to 2.6.21 / 2.7.5 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A memory leak in OpenVPN version 2.5.0 through 2.5.11, 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote attackers with a valid tls-crypt-v2 client key to potentially cause a denial of service

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OpenVPN versions 2.5.0-2.5.11, 2.6.0-2.6.20, and 2.7_alpha1-2.7.4 contain a memory leak that can be triggered by remote attackers possessing a valid tls-crypt-v2 client key, potentially leading to denial of service through resource exhaustion.

MitigationUpgrade to the latest OpenVPN version (2.5.12+, 2.6.21+, or 2.7.5+) to obtain the patch. As a temporary measure, consider rotating tls-crypt-v2 client keys to invalidate potentially compromised credentials.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OpenvpnApplication
Affected:>= 2.5.0, <= 2.5.11>= 2.6.0, < 2.6.21>= 2.7, < 2.7.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed OpenVPN version
    Run 'openvpn --version' or check the package manager (e.g., 'dpkg -l openvpn', 'rpm -qi openvpn')
    Affected if The version falls within 2.5.0-2.5.11, 2.6.0-2.6.20, or 2.7.0-2.7.4
  2. Identify OpenVPN server configuration files
    Locate .ovpn or .conf files in /etc/openvpn/, /etc/openvpn/server/, or custom paths referenced in startup scripts
    Affected if Configuration files exist and the server is running as a TLS server
  3. Check if tls-crypt-v2 is enabled in the server configuration
    Inspect server config files for the directive 'tls-crypt-v2' or 'tls-crypt' (the vulnerability affects tls-crypt-v2 specifically)
    Affected if The directive 'tls-crypt-v2' is present in the server configuration
  4. Verify presence of tls-crypt-v2 client keys
    Check for .key or .pem files referenced by 'tls-crypt-v2' directive in config, typically in /etc/openvpn/keys/ or same directory as config
    Affected if Valid tls-crypt-v2 client keys exist on the server and could be used by an attacker
  5. Monitor for memory exhaustion symptoms
    Observe OpenVPN process memory usage over time using 'ps aux | grep openvpn' or 'top'/'htop', especially after multiple client connections
    Affected if Memory usage grows continuously without being freed, indicating the leak is being triggered

You are affected if your OpenVPN version is 2.5.0-2.5.11, 2.6.0-2.6.20, or 2.7.0-2.7.4 AND tls-crypt-v2 is enabled in your server configuration with active client keys.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.6.21 / 2.7.5 or later
Fixed in 2.6.212.7.5
Interim mitigation

Upgrade to the latest OpenVPN version (2.5.12+, 2.6.21+, or 2.7.5+) to obtain the patch. As a temporary measure, consider rotating tls-crypt-v2 client keys to invalidate potentially compromised credentials.

Recommended fix High confidence

Upgrade to OpenVPN 2.5.12+, 2.6.21+, or 2.7.5+ (latest stable release recommended)

  1. 1. Identify the currently installed OpenVPN version using 'openvpn --version' or 'openvpn -v'
  2. 2. Based on your current version branch, upgrade to the minimum fixed version: for 2.5.x upgrade to 2.5.12+, for 2.6.x upgrade to 2.6.21+, for 2.7.x upgrade to 2.7.5+
  3. 3. On Linux/Unix systems, use your package manager to upgrade (e.g., apt update && apt install openvpn, yum update openvpn, or dnf update openvpn)
  4. 4. Verify the new version is installed correctly with 'openvpn --version'
  5. 5. Restart the OpenVPN service to load the fixed version (systemctl restart openvpn@<config-name> or service openvpn restart)
  6. 6. Monitor system memory usage after restart to confirm the memory leak is resolved

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Openvpn Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,540
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-13698 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data