Is CVE-2020-0688 being actively exploited?

Yes. CVE-2020-0688 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on November 3, 2021.

What is the CVSS score for CVE-2020-0688?

CVE-2020-0688 has a CVSS 3.1 base score of 8.8 (HIGH).

CVE-2020-0688

HIGH · CVSS 8.8CISA KEV: actively exploitedEPSS 100.0%EU EUVD: exploited

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

CVSS score: 8.8 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-287
EPSS score: 100.0% (100th percentile)
In CISA KEV: Yes, added November 3, 2021
In EU EUVD: Yes (EUVD-2020-2181)
Published: February 11, 2020
NVD last modified: June 17, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability

Added to the KEV catalog on November 3, 2021; federal remediation due May 3, 2022. Known to be used in ransomware campaigns.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2020-2181 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on October 21, 2025.

View on the EU Vulnerability Database

Affected products

microsoft / exchange server
microsoft / exchange server
microsoft / exchange server
microsoft / exchange server
microsoft / exchange server
microsoft / exchange server

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

Microsoft Exchange Server 2010 SP1 Enterprise (English) 64-bit - Microsoft Corporation - Common Criteria Certificate Number: 2011/72 - archived

References

http://packetstormsecurity.com/files/156592/Microsoft-Exchange-2019-15.2.221.12-Remote-Code-Execution.html(Exploit, Third Party Advisory, VDB Entry)
http://packetstormsecurity.com/files/156620/Exchange-Control-Panel-Viewstate-Deserialization.html(Exploit, Third Party Advisory, VDB Entry)
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0688(Patch, Vendor Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0688(US Government Resource)
https://www.zerodayinitiative.com/advisories/ZDI-20-258/(Third Party Advisory, VDB Entry)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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