CVE-2026-70355

Microsoft SharePoint Server Elevation of Privilege Vulnerability

At a glance

Severity: HIGH 7.3
EPSS: EPSS 0.78 % · percentile 56 (2026-10-27)
State: PUBLISHED
Published: 2026-08-11
Updated: 2026-10-21
Assigner: microsoft
NVD status: Analyzed

Description

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 7.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N	microsoft
CVSS 3.1	HIGH 7.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N	NVD · secure@microsoft.com (Secondary)
CVSS 3.1	HIGH 8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N	NVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

CWE-79

European references

ENISA EUVD · EUVD-2026-56602
GCVE · GCVE-0-2026-70355

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:2019:*:*:*:*:*:*:*

Affected products

Product	Versions
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-2026-70355

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