How severe is CVE-2021-35066?

CVE-2021-35066 has a CVSS 3.x base score of 9.8, 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 high.

Is CVE-2021-35066 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-35066?

CVE-2021-35066 affects Connectwise Automate. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-35066?

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-2021-35066 published?

CVE-2021-35066 was published on 2021-06-21 and last updated on 2026-06-17.

CVE-2021-35066

CVE-2021-35066 is a critical-severity vulnerability in Connectwise Automate with a CVSS 3.x base score of 9.8. 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-611.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-611
Affected product: Connectwise Automate
Published: 2021-06-21
Last modified: 2026-06-17

Description

An XXE vulnerability exists in ConnectWise Automate before 2021.0.6.132.

Frequently asked questions

What is CVE-2021-35066?: An XXE vulnerability exists in ConnectWise Automate before 2021.0.6.132.
How severe is CVE-2021-35066?: CVE-2021-35066 has a CVSS 3.x base score of 9.8, 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 high.
Is CVE-2021-35066 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-35066?: CVE-2021-35066 affects Connectwise Automate. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-35066?: 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-2021-35066 published?: CVE-2021-35066 was published on 2021-06-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:connectwise:automate:*:*:*:*:*:*:*:*

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