Skip to main content
Threat Radar animated logo

Retransmissions of ACK packet ID in OpenVPN through 2.6.22 and 2.7.6 allow remote unauthenticated attackers to cause a denial of service via crafted… (CVE-2026-84732)

0
Medium
VulnerabilityCVE-2026-84732gcveosvubuntu-cve-2026-84732cve-2026-84732ubuntu-pro-14-04-ltsubuntu-pro-16-04-ltsubuntu-pro-18-04-ltsubuntu-20-04-ltsubuntu-22-04-ltsubuntu-24-04-ltsubuntu-26-04-lts
Published: 09/04/2026 (09/04/2026, 00:00:00 UTC)
Source: GCVE Database
Product: openvpn

Description

Retransmissions of ACK packet ID in OpenVPN through 2.6.22 and 2.7.6 allow remote unauthenticated attackers to cause a denial of service via crafted inputs that trigger a timeout integer overflow

CVSS v4.0

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vuln. Confidentiality
None
Vuln. Integrity
None
Vuln. Availability
High
Subsq. Confidentiality
None
Subsq. Integrity
None
Subsq. Availability
Low
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L

Affected software

Ubuntu:Pro:14.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=esm-infra-legacy/trusty
Affected versions
=2.3.2-4ubuntu1=2.3.2-5ubuntu1=2.3.2-7ubuntu1=2.3.2-7ubuntu2=2.3.2-7ubuntu3=2.3.2-7ubuntu3.1=2.3.2-7ubuntu3.2=2.3.2-7ubuntu3.2+esm1=2.3.2-7ubuntu3.2+esm2
Ubuntu:Pro:16.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=esm-infra/xenial
Affected versions
=2.3.7-1ubuntu1=2.3.7-2ubuntu1=2.3.8-1ubuntu1=2.3.10-1ubuntu1=2.3.10-1ubuntu2=2.3.10-1ubuntu2.1=2.3.10-1ubuntu2.2=2.3.10-1ubuntu2.2+esm1=2.3.10-1ubuntu2.2+esm2
Ubuntu:Pro:18.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=esm-infra/bionic
Affected versions
=2.4.3-4ubuntu1=2.4.4-1ubuntu1=2.4.4-2ubuntu1=2.4.4-2ubuntu1.1=2.4.4-2ubuntu1.2=2.4.4-2ubuntu1.3=2.4.4-2ubuntu1.5=2.4.4-2ubuntu1.6=2.4.4-2ubuntu1.7=2.4.4-2ubuntu1.7+esm1
Ubuntu:20.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=focal
Affected versions
=2.4.7-1ubuntu2=2.4.7-1ubuntu2.20.04.2=2.4.7-1ubuntu2.20.04.3=2.4.7-1ubuntu2.20.04.4=2.4.12-0ubuntu0.20.04.1=2.4.12-0ubuntu0.20.04.2
Ubuntu:22.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=jammy
Affected versions
=2.5.1-3ubuntu1=2.5.1-3ubuntu2=2.5.1-3ubuntu4=2.5.1-3ubuntu5=2.5.5-1ubuntu1=2.5.5-1ubuntu3=2.5.5-1ubuntu3.1=2.5.9-0ubuntu0.22.04.2=2.5.9-0ubuntu0.22.04.3=2.5.11-0ubuntu0.22.04.1=2.5.11-0ubuntu0.22.04.3=2.5.11-0ubuntu0.22.04.4
Ubuntu:24.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=noble
Affected versions
=2.6.5-0ubuntu1=2.6.7-1ubuntu1=2.6.9-1ubuntu2=2.6.9-1ubuntu3=2.6.9-1ubuntu4=2.6.9-1ubuntu4.1=2.6.12-0ubuntu0.24.04.1=2.6.12-0ubuntu0.24.04.3=2.6.14-0ubuntu0.24.04.1=2.6.14-0ubuntu0.24.04.2=2.6.14-0ubuntu0.24.04.3=2.6.19-0ubuntu0.24.04.1=2.6.19-0ubuntu0.24.04.2=2.6.19-0ubuntu0.24.04.3
Ubuntu:26.04:LTSmore threats →ghsa
openvpn
pkg:deb/ubuntu/openvpn?arch=source&distro=resolute
Affected versions
=2.6.14-2ubuntu1=2.6.15-1ubuntu1=2.7.0~rc5-1ubuntu5=2.7.0~rc6-1ubuntu1=2.7.0-1ubuntu1=2.7.0-1ubuntu1.1=2.7.0-1ubuntu1.2

Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/11/2026, 22:47:42 UTC

Technical Analysis

CVE-2026-84732 describes a denial of service vulnerability in OpenVPN through versions 2.6.22 and 2.7.6. The flaw arises from retransmissions of ACK packet IDs that, when crafted maliciously, trigger a timeout integer overflow. This overflow allows remote unauthenticated attackers to cause the OpenVPN service to crash or become unavailable. The vulnerability affects numerous Ubuntu-specific OpenVPN package versions as enumerated. There is no indication of active exploitation in the wild or a provided patch status in the data.

Potential Impact

Remote unauthenticated attackers can cause a denial of service condition in affected OpenVPN versions by sending specially crafted ACK packet retransmissions that trigger a timeout integer overflow. This results in service disruption but does not indicate code execution or data compromise.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the data. Until a patch is available, consider restricting access to OpenVPN services from untrusted networks to reduce exposure.

Pro Console: star threats, build custom feeds, automate alerts via Slack, email & webhooks.Upgrade to Pro

Technical Details

Gcve Source
db.gcve.eu
Osv Id
UBUNTU-CVE-2026-84732
Osv Schema Version
1.7.0
Ecosystems
["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:26.04:LTS"]
Cvss Version
4.0

Threat ID: 6aa47ebf55bf5e2cf58579e7

Added to database: 09/11/2026, 22:20:47 UTC

Last enriched: 09/11/2026, 22:47:42 UTC

Last updated: 09/12/2026, 00:47:07 UTC

Views: 3

Community Reviews

0 reviews

Crowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.

Sort by
Loading community insights…

Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.

Actions

PRO

Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.

Please log in to the Console to use AI analysis features.

Need more coverage?

Upgrade to Pro Console for AI refresh and higher limits.

For incident response and remediation, OffSeq services can help resolve threats faster.

Latest Threats

Breach by OffSeqOFFSEQFRIENDS — 25% OFF

Check if your credentials are on the dark web

Instant breach scanning across billions of leaked records. Free tier available.

Scan now
OffSeq TrainingCredly Certified

Lead Pen Test Professional

Technical5-day eLearningPECB Accredited
View courses