CVE-2026-56164

Analyzed
Published: 14 Jul 2026, 17:05
Last modified:20 Aug 2026, 17:01

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (nvd)
EPSS Score
22.44% HIGH
22% probability 0.00%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

14 Jul 2026, 17:05
Published
Vulnerability first disclosed
14 Jul 2026, 00:00
Added to CISA KEV
Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability
17 Jul 2026, 00:00
CISA Remediation Due
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.
20 Aug 2026, 17:01
Last Modified
Vulnerability information updated

Description

Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:F/RL:O/RC:C
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 22.44%• Percentile: 98%

Techniques & Countermeasures

  • CWE-306•Missing Authentication for Critical Function

    The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

Affected Systems

  • microsoft•microsoft sharepoint enterprise server 2016

    ≥ 16.0.0, < 16.0.5561.1001

  • microsoft•microsoft sharepoint server 2019

    ≥ 16.0.0, < 16.0.10417.20175

  • microsoft•microsoft sharepoint server subscription edition

    ≥ 16.0.0, < 16.0.19725.20434

  • microsoft•sharepoint_server

    < 16.0.19725.20434 | 2016 | 2019

References (2)