Microsoft SharePoint Server: Cross-site scripting leading to spoofing
Summary
Microsoft SharePoint Server Subscription Edition (on-premises) contains a cross-site scripting flaw in web page generation that allows an authorized attacker to perform spoofing over the network. The attacker needs a low-privileged valid account and must induce user interaction, such as opening a crafted page or link. Successful exploitation could expose data or user actions in the browser, with high impact on confidentiality and integrity.
Affected
- Microsoft SharePoint Server Subscription Edition 16.0.0 before 16.0.20326.20278
- Only the listed Subscription Edition product is confirmed; SharePoint 2019 and 2016 are not listed for this CVE
- Microsoft 365 SharePoint Online is not in scope
Fixed in
- Build 16.0.20326.20278 (November 2026 CU, KB 5002945), to be confirmed against the MSRC advisory
- Farms still at the September 2025 CU need a permissions fix script before the update installs
Workaround
Unknown.
Exploitation
- No confirmed exploitation found at the time of research
- CISA SSVC: exploitation none, automatable no, technical impact total
- NVD status: Awaiting Analysis; KEV status not confirmed by CISA
- No public proof of concept found
Our recommendation
- Check whether any SharePoint Server Subscription Edition farm runs below build 16.0.20326.20278
- Verify the fixed build against the MSRC advisory, check the September 2025 CU prerequisite, then patch
- Treat internet-facing farms as urgent and review their exposure; avoid direct internet exposure of SharePoint servers
- Recheck NVD and CISA KEV, as the status may change
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Spoofing – Microsoft Office SharePoint
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Microsoft Office
- Updates (KB)
- KB5002945
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-110045 msrc.microsoft.com
- CVE Record CVE-2026-110045 www.cve.org
- Stefan Gossner: SharePoint security fixes November 2026 blog.stefan-gossner.com
- Stefan Gossner: November 2026 CU for SharePoint Subscription Edition blog.stefan-gossner.com
- CERT-EU Security Advisory 2026-009 cert.europa.eu
- Resecurity: July 2026 SharePoint attacks www.resecurity.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 06:31.
Original description (NVD)
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.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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