How severe is CVE-2017-16726?

CVE-2017-16726 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2017-16726 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-16726?

CVE-2017-16726 affects Beckhoff Twincat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-16726?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2017-16726 published?

CVE-2017-16726 was published on 2018-06-27 and last updated on 2026-06-17.

CVE-2017-16726

CVE-2017-16726 is a critical-severity vulnerability in Beckhoff Twincat with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-326.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-326
Affected product: Beckhoff Twincat
Published: 2018-06-27
Last modified: 2026-06-17

Description

Beckhoff TwinCAT supports communication over ADS. ADS is a protocol for industrial automation in protected environments. ADS has not been designed to achieve security purposes and therefore does not include any encryption algorithms because of their negative effect on performance and throughput. An attacker can forge arbitrary ADS packets when legitimate ADS traffic is observable.

Frequently asked questions

What is CVE-2017-16726?: Beckhoff TwinCAT supports communication over ADS. ADS is a protocol for industrial automation in protected environments. ADS has not been designed to achieve security purposes and therefore does not include any encryption algorithms because of their negative effect on performance and throughput. An attacker can forge arbitrary ADS packets when legitimate ADS traffic is observable.
How severe is CVE-2017-16726?: CVE-2017-16726 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2017-16726 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-16726?: CVE-2017-16726 affects Beckhoff Twincat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-16726?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-16726 published?: CVE-2017-16726 was published on 2018-06-27 and last updated on 2026-06-17.

References

https://download.beckhoff.com/download/Document/product-security/Advisories/advisory-2017-001.pdf

Affected products (1)

cpe:2.3:a:beckhoff:twincat:-:*:*:*:*:*:*:*

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