Microsoft SharePoint Server Subscription Edition: Elevation of privilege via incorrect authorization
Summary
Incorrect authorization in on-premises Microsoft SharePoint Server Subscription Edition allows an authenticated attacker with a valid low-privilege account to elevate privileges over the network. The CVSS vector indicates a changed scope and high impact on confidentiality, integrity and availability. Microsoft rates the issue as Important, while the CVSS score in the brief is 9.9 Critical; NVD analysis is pending.
Affected
- Microsoft SharePoint Server Subscription Edition, 16.0.0 to before 16.0.20326.20278 (official CVE record)
- SharePoint Online in Microsoft 365 is not affected by the on-premises fix.
Fixed in
- Microsoft November 2026 security update for SharePoint Server Subscription Edition, KB5002945, build 16.0.20326.20278 (mapping to this CVE not fully verified; confirm on the CVE-specific MSRC page)
Workaround
- Unknown. No vendor workaround is known; patching is the vendor remedy.
Exploitation
- No known exploitation in the wild at the time of writing. No public proof of concept found. CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
Our recommendation
- Inventory on-premises SharePoint Server Subscription Edition servers and compare build numbers with the fixed build.
- Apply the November 2026 security update (KB5002945) after verifying the fixed build on the Microsoft Security Update Guide.
- Until patched, restrict external access to SharePoint and review accounts with delegated or low privileges.
- Monitor authenticated SharePoint activity for unusual privilege changes.
- Recheck NVD and CISA KEV once analysis is published.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – 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
- Microsoft Security Update Guide: CVE-2026-120002 msrc.microsoft.com
- CVE Record CVE-2026-12002 www.cve.org
- Microsoft Security Update Guide (general) msrc.microsoft.com
- Microsoft KB5002927 SharePoint Subscription Edition update support.microsoft.com
- Stefan Gossner: SharePoint security fixes October 2026 blog.stefan-gossner.com
- CISA Bulletin SB26-033 www.cisa.gov
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 10 Nov 2026, 20:31.
Original description (NVD)
Incorrect authorization in Microsoft Office SharePoint allows an authorized attacker to elevate privileges 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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