CVE-2020-0688
Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability
- High 8.8
- Exploited: added to CISA KEV 3 Nov 2021
- Used in ransomware campaigns
Description
A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.
Key facts
- Published
- 11 Feb 2020
- Last changed
- 21 Oct 2025
- Assigned by
- microsoft
- KEV added
- 3 Nov 2021
- KEV fix due
- 3 May 2022
- Used in ransomware
- Yes, according to CISA
- EPSS
- 99.955% likely to be exploited in the next 30 days, higher than 99.975% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 8.8CVSS 3.1, Highfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft Exchange Server 2013 |
|
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 3 |
|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 14 |
|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 15 |
|
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 4 |
|
| Microsoft | Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 30 |
|
Timeline
- 11 Feb 2020 Published
- 3 Nov 2021 CVE-2020-0688 added to CISA KEV
- 3 Nov 2021 Added to the CISA KEV catalogue