CVE-2026-64921

Microsoft SharePoint Server Elevation of Privilege Vulnerability

At a glance

Severity: HIGH 8.8
EPSS: EPSS 0.94 % · percentile 61 (2026-10-27)
State: PUBLISHED
Published: 2026-08-11
Updated: 2026-10-21
Assigner: microsoft
NVD status: Analyzed

Description

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

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C	microsoft
CVSS 3.1	HIGH 8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	NVD · secure@microsoft.com (Secondary)

Weaknesses (CWE)

CWE-306

European references

ENISA EUVD · EUVD-2026-56722
GCVE · GCVE-0-2026-64921

CERT-FR advisories

CERTFR-2026-AVI-1004 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:* < 16.0.19725.20522
cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*

Affected products

Product	Versions
Microsoft · Microsoft SharePoint Enterprise Server 2016	affected 16.0.0 < 16.0.5565.1001
Microsoft · Microsoft SharePoint Server 2019	affected 16.0.0 < 16.0.10417.20198
Microsoft · Microsoft SharePoint Server Subscription Edition	affected 16.0.0 < 16.0.19725.20522

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64921

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD