CVE-2026-64900: Microsoft SharePoint Server Spoofing Vulnerability

highCVSS 7.3CVE-2026-64900

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

CSIRTS triage

vendor: Microsoft product: SharePoint Server Cross-site scripting

What: Cross-site scripting vulnerability in SharePoint web page generation enables spoofing.
Who is affected: Authorized users with network access to SharePoint deployments.
Urgency: High; CVSS 7.3 indicates elevated severity despite authentication requirement.
Action: Apply Microsoft SharePoint Server security update for CVE-2026-64900.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.3
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64900

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-649000.45% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64900	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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