OpenvpnApplication
CVE-2026-35058
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 · uneditedImproper validation of packet length during tls-crypt-v2 key extraction in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows authenticated attackers to trigger a fatal assertion and cause a denial of service via a specially crafted packet.
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 confidenceOpenVPN versions 2.6.0-2.6.19 and 2.7_alpha1-2.7.1 fail to properly validate packet length during tls-crypt-v2 key extraction. An authenticated attacker sending a specially crafted packet with invalid length can trigger a fatal assertion, causing the OpenVPN process to crash and resulting in denial of service.
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
>= 2.6.0, < 2.6.20>= 2.7, < 2.7.2CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify OpenVPN installation and versionRun 'openvpn --version' or check the package manager (dpkg -l openvpn, rpm -q openvpn) to determine the installed versionAffected if The version number falls within 2.6.0-2.6.19 or 2.7_alpha1-2.7.1
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Locate OpenVPN server or client configuration filesCheck for configuration files in /etc/openvpn/, /etc/openvpn/server/, /etc/openvpn/client/, or custom paths referenced in systemd service filesAffected if Configuration files exist indicating OpenVPN is in use
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Determine if tls-crypt-v2 is enabledInspect the configuration files for the 'tls-crypt-v2' directive (not just 'tls-crypt'). Search using: grep -r 'tls-crypt-v2' /etc/openvpn/ or examine the specific .ovpn or .conf filesAffected if The directive 'tls-crypt-v2' is present and uncommented in the configuration
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Verify OpenVPN process is running and accepting connectionsCheck active processes with 'ps aux | grep openvpn' or verify the service status with 'systemctl status openvpn'Affected if OpenVPN is actively running with tls-crypt-v2 configured on a vulnerable version
The environment is affected if OpenVPN version is 2.6.0 through 2.6.19 or 2.7_alpha1 through 2.7.1 AND tls-crypt-v2 is enabled in the configuration.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor data2.6.202.7.2
Upgrade OpenVPN to version 2.6.20 or later / 2.7.2 or later. Alternatively, if immediate upgrade is not feasible, restrict network access to trusted peers only using firewall rules or IP allowlisting to reduce attack surface.
Fix this in Openvpn
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-35058 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-35058 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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