CVE-2026-45479: Microsoft SharePoint Server Spoofing Vulnerability

mediumCVSS 4.6CVE-2026-45479

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: Microsoft SharePoint Server Cross-site scripting

What: This vulnerability allows an authorized attacker to perform spoofing over a network due to improper input neutralization.
Who is affected: Deployments of Microsoft SharePoint Server.
Urgency: Remediation is medium urgency due to the medium severity rating.
Action: Patch Microsoft SharePoint Server for CVE-2026-45479.

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: medium — CVSS 4.6
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45479

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-2026-454790.51% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 40% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45479	coverage & exploitation status	NVD · CVE.org

Recent advisories for Microsoft SharePoint Server

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

criticalexploitedAL26-015 - Critical vulnerability impacting Microsoft SharePoint Server – CVE-2026-45659cccs · 2026-07-02
high[UPDATE] [high] Microsoft SharePoint Server 2016 and SharePoint Server 2019: Vulnerability allows code executi…cert-bund · 2026-07-02
criticalexploitedCVE-2026-45659: Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerabilitycisa-kev · 2026-07-01
mediumCVE-2026-45468: Microsoft SharePoint Server Spoofing Vulnerabilitymsrc · 2026-06-09
mediumCVE-2026-45467: Microsoft SharePoint Server Spoofing Vulnerabilitymsrc · 2026-06-09
mediumCVE-2026-45453: Microsoft SharePoint Server Spoofing Vulnerabilitymsrc · 2026-06-09