CVE-2020-16875Exchange Server Vulnerability
A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.
Published Sep 11, 2020 · Updated Feb 23, 2026
Key Facts
Patch immediately- CVE-2020-16875 is a high-severity vulnerability (CVSS 7.2 v3.1) affecting Exchange Server (Microsoft).
- It is exploited in the wild, listed in Industry KEV feed since Oct 21, 2022. Public exploit code is available.
- EPSS estimates a 46% probability of exploitation in the next 30 days.
- Fixed versions are available, including Exchange Server publication.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v3.1
7.2
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
46%
Higher than 98.8% of all scored CVEs
Exploit maturity
Weaponized
ATLAS score
66/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Oct 21, 2022
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Weaponized
Public exploit code
2
Proof-of-concept links
In-the-wild evidence
2
Reports of active use
Advisories And Exploit References
Description
A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.
An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the System user. Exploitation of the vulnerability requires an authenticated user in a certain Exchange role to be compromised.
The security update addresses the vulnerability by correcting how Microsoft Exchange handles cmdlet arguments.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Oct 21, 2022 | n/a | Not reported |
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Exchange ServerMicrosoft | 2016-cumulative_update_16, 2016-cumulative_update_17, 2019-cumulative_update_5, 2019-cumulative_update_6 | publication |
Patched Releases
Exchange Server
publication
Timeline
Publicly disclosed
Sep 11, 2020
Added to Industry KEV feed
Oct 21, 2022
Last updated
Feb 23, 2026
Weakness Type
- CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
- CWE-269 Improper Privilege Management
FAQ
Common Questions.
A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.
Affected: Exchange Server (Microsoft) versions 2016-cumulative_update_16, 2016-cumulative_update_17, 2019-cumulative_update_5, 2019-cumulative_update_6. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Oct 21, 2022.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Exchange Server publication.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2020-16875 On Your Attack Surface?
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