CVE-2026-56164
CriticalExploitedPublic exploitMissing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
Published Jul 14, 2026 · Updated Oct 8, 2026
Key Facts
Patch immediately- CVE-2026-56164 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Sharepoint Server (Microsoft), Sharepoint Server 2016 (Microsoft), Sharepoint Server 2019 (Microsoft) and 2 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jul 14, 2026. Public exploit code is available.
- EPSS estimates a 1.0% probability of exploitation in the next 30 days.
- Fixed versions are available, including Microsoft SharePoint Enterprise Server 2016 16.0.5561.1001, Sharepoint Server 16.0.19725.20434, Sharepoint Server 2019 16.0.10417.20175.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
1.0%
Higher than 62.5% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-56164 brief as a PDF
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Description
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Jul 14, 2026 | Jul 17, 2026 | Not reported |
| Industry KEV feed | Jul 14, 2026 | Jul 17, 2026 | Not reported |
| CIRCL KEV | Jul 14, 2026 | Jul 17, 2026 | Not reported |
| ENISA EUVD | Jul 14, 2026 | n/a | Not reported |
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.
Affected Products
9 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Sharepoint ServerMicrosoft | 2016, 2019 | 16.0.19725.20434 |
| Sharepoint Server 2016Microsoft | See advisory | 16.0.5561.1001 |
| Sharepoint Server 2019Microsoft | >= 16.0.0 | 16.0.10417.20175 |
| Microsoft SharePoint Enterprise Server 2016 | >= 16.0.0 | 16.0.5561.1001 |
| Microsoft SharePoint Server Subscription Edition | >= 16.0.0 | 16.0.19725.20434 |
Patched Releases
Microsoft SharePoint Enterprise Server 2016
16.0.5561.1001
Sharepoint Server
16.0.19725.20434
Sharepoint Server 2019
16.0.10417.20175
Microsoft SharePoint Server Subscription Edition
16.0.19725.20434
Timeline
Publicly disclosed
Jul 14, 2026
Added to CISA KEV
Jul 14, 2026
Added to Industry KEV feed
Jul 14, 2026
Added to CIRCL KEV
Jul 14, 2026
Added to ENISA EUVD
Jul 14, 2026
Last updated
Oct 8, 2026
Weakness Type
- CWE-306 Missing Authentication for Critical Function
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
Affected: Sharepoint Server (Microsoft) versions 2016, 2019; Sharepoint Server 2016 (Microsoft); Sharepoint Server 2019 (Microsoft) versions >= 16.0.0, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jul 14, 2026.
Yes. It was added on Jul 14, 2026 with a federal remediation due date of Jul 17, 2026.
Public exploit code is available.
Fixed versions are available, including Microsoft SharePoint Enterprise Server 2016 16.0.5561.1001, Sharepoint Server 16.0.19725.20434, Sharepoint Server 2019 16.0.10417.20175.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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