How severe is CVE-2020-17117?

CVE-2020-17117 has a CVSS 3.x base score of 6.6, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-17117 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 49% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-17117?

CVE-2020-17117 primarily affects Microsoft Exchange Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-17117?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-17117 published?

CVE-2020-17117 was published on 2020-12-10 and last updated on 2026-06-17.

CVE-2020-17117

CVE-2020-17117 is a medium-severity vulnerability in Microsoft Exchange Server with a CVSS 3.x base score of 6.6. Its EPSS exploit-prediction score of 49% places it in the 99th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: Medium (CVSS 3.x base score 6.6)
CVSS v2: 9.0
EPSS exploit prediction: 49% (99th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Exchange Server
Published: 2020-12-10
Last modified: 2026-06-17

Description

Microsoft Exchange Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2020-17117?: Microsoft Exchange Remote Code Execution Vulnerability
How severe is CVE-2020-17117?: CVE-2020-17117 has a CVSS 3.x base score of 6.6, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-17117 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 49% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-17117?: CVE-2020-17117 primarily affects Microsoft Exchange Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-17117?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-17117 published?: CVE-2020-17117 was published on 2020-12-10 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:*

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