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Microsoft SharePoint Server Cross-Site Scripting Spoofing Vulnerability

IdentifiersCVE-2026-47634CWE-79· Improper Neutralization of Input…

CVE-2026-47634 is a cross-site scripting (XSS) vulnerability in Microsoft Office SharePoint / Microsoft SharePoint Server caused by improper neutralization of input during web page generation. Microsoft describes the issue as allowing an authorized attacker to perform spoofing over a network. The available advisory information indicates that the flaw stems from insufficient output neutralization of attacker-controlled content rendered in a SharePoint web context, enabling malicious script or crafted content to be presented to a victim through SharePoint. The vulnerability is associated with low-privilege authorized access and requires user interaction, specifically convincing a user to open a malicious link.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an authorized low-privilege attacker to perform spoofing against users of the vulnerable SharePoint deployment over the network. In practical terms, this can enable attacker-controlled script execution in the victim's browser within the SharePoint context, facilitating deceptive content presentation, session- or context-based abuse available to client-side script, and other browser-side actions consistent with XSS-driven spoofing. The provided sources specifically characterize the primary impact as spoofing rather than server-side code execution or privilege escalation on the SharePoint host.

Mitigation

If you can’t patch tonight, do this now.

No vendor-specific mitigation beyond patching was provided in the primary advisory. Until updates are applied, reduce exposure by restricting SharePoint access to trusted users where feasible, monitoring for suspicious SharePoint links and exploitation attempts, and warning users not to open unexpected or untrusted SharePoint URLs. General compensating controls such as web application monitoring, content validation, and limiting unnecessary SharePoint exposure may reduce risk, but the authoritative fix is the Microsoft security update.

Remediation

Patch, then assume compromise.

Apply the Microsoft security update for the affected SharePoint product. Per the Microsoft advisory, for SharePoint Server 2016, the update for SharePoint Enterprise Server 2016 also applies, and customers running either version should install the security update to be protected. Additional advisory context recommends installing the June 2026 Microsoft security updates and, for SharePoint Server Subscription Edition, ensuring the system is on the release version and installing update package build 16.0.19725.20384 where applicable.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationOffice Sharepointapplication
Microsoft CorporationSharepoint Enterprise Serverapplication
Microsoft CorporationSharepoint Serverapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app
What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2026-47634
NVD
nvd.nist.gov/vuln/detail/CVE-2026-47634
MITRE CWE · CWE-79
Improper Neutralization of Input During Web…
Vendor Advisory
msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47634