Exploitation evidence
Known exploited · CISA KEV listed
Added 2026-07-14. Ransomware campaign use: Unknown.
CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA due date: 2026-07-17. 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 SharePoint Enterprise Server 2016
Default status: Not specified
- affected: 16.0.0 to < 16.0.5561.1001 (custom)
Microsoft / Microsoft SharePoint Server 2019
Default status: Not specified
- affected: 16.0.0 to < 16.0.10417.20175 (custom)
Microsoft / Microsoft SharePoint Server Subscription Edition
Default status: Not specified
- affected: 16.0.0 to < 16.0.19725.20434 (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": 0.2733,
"percentile": 0.98087
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.01011,
"percentile": 0.63453
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.01011,
"percentile": 0.63411
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.01011,
"percentile": 0.63397
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.01011,
"percentile": 0.63376
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.01011,
"percentile": 0.63325
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.01011,
"percentile": 0.63298
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.01011,
"percentile": 0.63273
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.01011,
"percentile": 0.63215
}03 Nov 2026, 06:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-56164",
"options": [
{
"Exploitation": "active"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-14T18:45:11.388695Z",
"version": "2.0.3"
},
"type": "ssvc"
}
},
{
"other": {
"content": {
"dateAdded": "2026-07-14",
"reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56164"
},
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"providerMetadata": {
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}
],
"title": "CISA ADP Vulnrichment"
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],
"cna": {
"affected": [
{
"platforms": [
"x64-based Systems"
],
"product": "Microsoft SharePoint Enterprise Server 2016",
"vendor": "Microsoft",
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{
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"product": "Microsoft SharePoint Server Subscription Edition",
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"cpeApplicability": [
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"nodes": [
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{
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{
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"operator": "OR"
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],
"datePublic": "2026-07-14T14:00:00.000Z",
"descriptions": [
{
"lang": "en-US",
"value": "Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:F/RL:O/RC:C",
"version": "3.1"
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"problemTypes": [
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]
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],
"providerMetadata": {
"dateUpdated": "2026-11-01T17:32:49.364Z",
"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
"shortName": "microsoft"
},
"references": [
{
"name": "Microsoft SharePoint Server Elevation of Privilege Vulnerability",
"tags": [
"vendor-advisory",
"patch"
],
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56164"
}
],
"title": "Microsoft SharePoint Server Elevation of Privilege Vulnerability"
}
},
"cveMetadata": {
"assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
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"datePublished": "2026-07-14T17:05:12.313Z",
"dateReserved": "2026-06-19T13:53:31.988Z",
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"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.01011,
"percentile": 0.63174
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2026-56164",
"cwes": [
"CWE-306"
],
"dateAdded": "2026-07-14",
"dueDate": "2026-07-17",
"forensicTriage": "Yes",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-56164 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-56164",
"product": "SharePoint Server",
"requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.",
"shortDescription": "Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.",
"vendorProject": "Microsoft",
"vulnerabilityName": "Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability"
}