Exploitation evidence
Known exploited · CISA KEV listed
Added 2021-11-03. Ransomware campaign use: Known.
CISA required action: Apply updates per vendor instructions.
CISA due date: 2022-05-03. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
Microsoft / Microsoft Exchange Server 2013
Default status: Not specified
- affected: Cumulative Update 23
Microsoft / Microsoft Exchange Server 2019 Cumulative Update 3
Default status: Not specified
- affected: unspecified
Microsoft / Microsoft Exchange Server 2016 Cumulative Update 14
Default status: Not specified
- affected: unspecified
Microsoft / Microsoft Exchange Server 2016 Cumulative Update 15
Default status: Not specified
- affected: unspecified
Microsoft / Microsoft Exchange Server 2019 Cumulative Update 4
Default status: Not specified
- affected: unspecified
Microsoft / Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 30
Default status: Not specified
- affected: unspecified
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
CVE Program record ↗ · Download tracked evidence as JSON
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0688
- https://www.zerodayinitiative.com/advisories/ZDI-20-258/
- http://packetstormsecurity.com/files/156592/Microsoft-Exchange-2019-15.2.221.12-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/156620/Exchange-Control-Panel-Viewstate-Deserialization.html
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-0688
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.99955,
"percentile": 0.99974
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.99955,
"percentile": 0.99974
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.99955,
"percentile": 0.99974
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.99955,
"percentile": 0.99974
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.99955,
"percentile": 0.99974
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.99955,
"percentile": 0.99974
}06 Nov 2026, 06:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
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}05 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.99955,
"percentile": 0.99974
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.99955,
"percentile": 0.99974
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.99955,
"percentile": 0.99974
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.99955,
"percentile": 0.99974
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2020-0688",
"cwes": [
"CWE-287"
],
"dateAdded": "2021-11-03",
"dueDate": "2022-05-03",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Known",
"notes": "https://nvd.nist.gov/vuln/detail/CVE-2020-0688",
"product": "Exchange Server",
"requiredAction": "Apply updates per vendor instructions.",
"shortDescription": "Microsoft Exchange Server Validation Key fails to properly create unique keys at install time, allowing for remote code execution.",
"vendorProject": "Microsoft",
"vulnerabilityName": "Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability"
}