Microsoft SharePoint Server: Server-side request forgery in SharePoint
Summary
Microsoft SharePoint Server Subscription Edition (on-premises) contains a server-side request forgery (CWE-918) that is described by Microsoft as a spoofing vulnerability. An authenticated attacker with a low-privileged account on the network can trigger requests from the server, which may expose internal data. The attack complexity is high and no user interaction is required; the CVSS base score is 5.3 (medium). SharePoint Online and Microsoft 365 are not affected.
Affected
- Microsoft SharePoint Server Subscription Edition (on-premises) 16.0.0 before 16.0.20326.20278
- SharePoint 2016 and 2019: not listed for this CVE in the sources reviewed; check the MSRC entry.
Fixed in
- Build 16.0.20326.20278 (November 2026 CU, KB5002945)
Workaround
- No vendor-documented workaround specific to this CVE.
- Limit external exposure of SharePoint if patching is delayed.
- Review accounts with low privileges that can access the farm.
Exploitation
- No evidence of exploitation in the wild found.
- Not verified in the CISA KEV catalogue.
- No public proof of concept found.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact partial.
Our recommendation
- Install KB5002945 (build 16.0.20326.20278) on SharePoint Server Subscription Edition farms this week, starting with internet-facing farms.
- Run the SharePoint Products Configuration Wizard on every server after installation.
- Verify the installed build against the version listed by Microsoft.
- Review external exposure and monitor SharePoint logs for unusual outbound requests.
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
- CVE record www.cve.org
- MSRC Security Update Guide msrc.microsoft.com
- Zero Day Initiative November 2026 review www.zerodayinitiative.com
- Rapid7 Patch Tuesday November 2026 www.rapid7.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, 18:35.
Original description (NVD)
Server-side request forgery (ssrf) 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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