CVE-2026-18717Network attack vector

Protected communications interception via unchecked TLS certificate errors

Published Aug 27, 2026 · Updated Aug 27, 2026

Improper certificate validation in Applied Systems Engineering ASE2000 2.35 through 2.37 allows remote attackers to intercept IEC 104 TLS traffic. The IEC 60870-5-104 TLS client certificate validation logic accepts certificate error conditions instead of rejecting the peer. Man-in-the-middle attackers must gain a network position between the TLS client and intended peer; resulting access is limited to reading or modifying that session's communications.

CVSS severity7.4
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Applied Systems Engineering ASE2000 2.35 through 2.37 allows remote attackers to intercept IEC 104 TLS traffic. The IEC 60870-5-104 TLS client certificate validation logic accepts certificate error conditions instead of rejecting the peer. Man-in-the-middle attackers must gain a network position between the TLS client and intended peer; resulting access is limited to reading or modifying that session's communications.

The record

CVE
CVE-2026-18717
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
Applied Systems Engineering
Product
ASE2000 V2 RTU Test Set
Classifications
CWE-295, T0830
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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=2.25 <=2.37

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Applied Systems Engineering · ASE2000 V2 RTU Test Setversion=2.25 <=2.37

Published CVSS scores

7.4CISACVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/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.

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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-295Improper Certificate Validation
T0830Man 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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