Exploitation evidence
Known exploited · CISA KEV listed
Added 2024-08-21. Ransomware campaign use: Unknown.
CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA due date: 2024-09-11. 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 Cumulative Update 23
Default status: Not specified
- affected: 15.00.0 to < 15.00.1497.023 (custom)
Microsoft / Microsoft Exchange Server 2016 Cumulative Update 20
Default status: Not specified
- affected: 15.01.0 to < 15.01.2242.012 (custom)
Microsoft / Microsoft Exchange Server 2016 Cumulative Update 21
Default status: Not specified
- affected: 15.01.0 to < 15.01.2308.014 (custom)
Microsoft / Microsoft Exchange Server 2019 Cumulative Update 10
Default status: Not specified
- affected: 15.02.0 to < 15.02.0922.013 (custom)
Microsoft / Microsoft Exchange Server 2019 Cumulative Update 9
Default status: Not specified
- affected: 15.02.0 to < 15.02.0858.015 (custom)
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
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": 0.54056,
"percentile": 0.9902
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.54056,
"percentile": 0.99014
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.54056,
"percentile": 0.99012
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.54056,
"percentile": 0.99012
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.54056,
"percentile": 0.99012
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.54056,
"percentile": 0.99011
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.54056,
"percentile": 0.9901
}05 Nov 2026, 12:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
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}
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{
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"cna": {
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},
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}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.54056,
"percentile": 0.99008
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.54056,
"percentile": 0.99007
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.54056,
"percentile": 0.99006
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2021-31196",
"cwes": [],
"dateAdded": "2024-08-21",
"dueDate": "2024-09-11",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2021-31196; https://nvd.nist.gov/vuln/detail/CVE-2021-31196",
"product": "Exchange Server",
"requiredAction": "Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.",
"shortDescription": "Microsoft Exchange Server contains an information disclosure vulnerability that allows for remote code execution.",
"vendorProject": "Microsoft",
"vulnerabilityName": "Microsoft Exchange Server Information Disclosure Vulnerability"
}