CVE-2023-40236Network attack vector

SSH instance spoofing via reused host keys

Published Dec 25, 2023 · Updated Apr 23, 2025

Authentication bypass in Pexip VMR self-service portal before 3 allows man-in-the-middle attackers to spoof SSH instances. The appliance image reuses the same SSH host key across customer installations, so clients cannot distinguish a genuine portal from an impostor presenting that key. Exploitation requires active network interception and user interaction, after which the impostor can read, alter, or interrupt SSH traffic.

CVSS severity7.5
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Pexip VMR self-service portal before 3 allows man-in-the-middle attackers to spoof SSH instances. The appliance image reuses the same SSH host key across customer installations, so clients cannot distinguish a genuine portal from an impostor presenting that key. Exploitation requires active network interception and user interaction, after which the impostor can read, alter, or interrupt SSH traffic.

The record

CVE
CVE-2023-40236
Published
Dec 25, 2023
Updated
Apr 23, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-798, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
7.5PexipCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
5.3NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

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-798Use of Hard-coded Credentials
T1557Adversary-in-the-Middle

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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