Microsoft SharePoint Server: Server-side request forgery leading to privilege escalation
Summary
A server-side request forgery (SSRF) flaw in Microsoft Office SharePoint Server Subscription Edition (on-premises) allows an authorized attacker to elevate privileges over the network. The attacker needs a valid low-privilege account and the attack complexity is high. Microsoft rates the vulnerability as Important with a CVSS 3.1 base score of 7.5; no public exploit and no active exploitation are known.
Affected
- Microsoft SharePoint Server Subscription Edition (x64), versions 16.0.0 before 16.0.20326.20190
- SharePoint Server 2016 and 2019: unclear, check the affected-products table on the MSRC page
Fixed in
- SharePoint Server Subscription Edition: build 16.0.20326.20190 or later, October 13, 2026 security update KB5002927 (requires the release version of Subscription Edition)
- SharePoint Server 2016/2019: Unknown.
Workaround
No workaround documented. Patching is the only documented remedy.
Exploitation
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Microsoft exploit maturity: Unproven (E:U).
- EPSS: 0.00573.
- No public proof of concept found in the research; this does not prove that none exists.
Our recommendation
- Identify all SharePoint farms and their versions.
- Patch Subscription Edition farms to build 16.0.20326.20190 or later (KB5002927) within the normal monthly cycle; prioritise internet-facing farms.
- Review accounts with access to the farm, especially external, guest and self-registered accounts, and remove unneeded ones.
- Limit outbound connections from SharePoint servers to internal networks.
- Check SharePoint 2016/2019 farms against the MSRC table and plan migration, as these versions are out of extended support.
Information from Microsoft (Patch Tuesday October 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)
- KB5002927
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-70202 msrc.microsoft.com
- Microsoft support: SharePoint hotfix KB5002927 support.microsoft.com
- OpenCVE: CVE-2026-70202 app.opencve.io
- Vulners: CVELIST:CVE-2026-70202 vulners.com
- Computerworld: October Patch Tuesday 2026 www.computerworld.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 2 Nov 2026, 18:57.
Original description (NVD)
Server-side request forgery (ssrf) 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.
Affected? We can help.
We check whether your systems are affected, install updates and close the gap – continuously with the System Health Checker if you wish.