CVE-2025-2704Network attack vector

Server crash via repeated wrapped-key setup

Published Apr 2, 2025 · Updated Oct 23, 2025

Denial of service in OpenVPN 2.6.1 through 2.6.13 allows remote attackers to crash TLS-crypt-v2 servers via replayed packets. The handshake path lets a later control packet repeat TLS-crypt-v2 wrapped-client-key setup instead of limiting key extraction to the session's initial packet, reaching an assertion that aborts the process. Exploitation requires a valid TLS-crypt-v2 client key or the ability to observe and inject handshake traffic; no data disclosure, integrity loss, or code execution is reported.

CVSS severity7.5
High
EPSS probability0.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in OpenVPN 2.6.1 through 2.6.13 allows remote attackers to crash TLS-crypt-v2 servers via replayed packets. The handshake path lets a later control packet repeat TLS-crypt-v2 wrapped-client-key setup instead of limiting key extraction to the session's initial packet, reaching an assertion that aborts the process. Exploitation requires a valid TLS-crypt-v2 client key or the ability to observe and inject handshake traffic; no data disclosure, integrity loss, or code execution is reported.

The record

CVE
CVE-2025-2704
Published
Apr 2, 2025
Updated
Oct 23, 2025
Vendor
OpenVPN Inc.
Product
OpenVPN
Classifications
CWE-754, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 23, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.1 <=2.6.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenVPN Inc. · OpenVPNversion=2.6.1 <=2.6.13

Published CVSS scores

6.0SUSECVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9SUSECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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