CVE-2023-46850Network attack vector

Memory disclosure via freed send-buffer transmission

Published Nov 11, 2023 · Updated Jun 23, 2026

Use-after-free in OpenVPN 2.6.0 through 2.6.6 allows remote attackers to receive freed send-buffer contents over TLS. The packet-sending path retains a reference to a send buffer after free() releases it, then transmits bytes from the reclaimed allocation to the connected peer. All TLS configurations are exposed, including Access Server 2.11.0 through 2.11.3 and 2.12.0 through 2.12.2; confirmed impact is process-memory disclosure, while the source record also reports remote code execution.

CVSS severity9.8
Critical
EPSS probability2.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in OpenVPN 2.6.0 through 2.6.6 allows remote attackers to receive freed send-buffer contents over TLS. The packet-sending path retains a reference to a send buffer after free() releases it, then transmits bytes from the reclaimed allocation to the connected peer. All TLS configurations are exposed, including Access Server 2.11.0 through 2.11.3 and 2.12.0 through 2.12.2; confirmed impact is process-memory disclosure, while the source record also reports remote code execution.

The record

CVE
CVE-2023-46850
Published
Nov 11, 2023
Updated
Jun 23, 2026
Vendor
OpenVPN Inc.
Product
OpenVPN Access Server
Classifications
CWE-416
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 11, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 2026Record 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=2.11.0 <=2.11.3
  2. Affected versionversion=2.12.0 <=2.12.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenVPN Inc. · OpenVPN Access Serverversion=2.11.0 <=2.11.3; version=2.12.0 <=2.12.2
OpenVPN Inc. · OpenVPNversion=2.6.0 <=2.6.6

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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