Microsoft SharePoint Server: Path traversal allowing remote code execution
Summary
Microsoft SharePoint Server Subscription Edition contains a path traversal flaw (CWE-22) in Microsoft Office SharePoint. An authorized attacker with low privileges on the network can execute code, with a CVSS base score of 8.8. Exposure is highest for internet-facing on-premises farms where users, including external or guest accounts, can authenticate.
Affected
- SharePoint Server Subscription Edition: 16.0.0 up to but not including 16.0.20326.20190
- SharePoint Server 2016 and 2019: unverified. Some aggregators list them as affected, but this has not been confirmed by Microsoft or NVD.
Fixed in
- SharePoint Server Subscription Edition: KB5002927, build 16.0.20326.20190 or later
- SharePoint Server 2016 and 2019: no confirmed fix found. Check the MSRC page and the vendor KB pages.
Workaround
Unknown. The CVE record and Microsoft list no workaround. A generic recommendation from an aggregator (restrict requests to designated application directories and reject path traversal patterns) is not verified by Microsoft and does not replace the patch.
Exploitation
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total
- Not listed in CISA KEV
- Microsoft exploit code maturity: Unproven
- No public proof of concept found; EPSS about 0.98%
- No known exploitation at the time of research
Our recommendation
- Patch SharePoint Server Subscription Edition to build 16.0.20326.20190 or later (KB5002927) promptly
- Confirm with Microsoft whether SharePoint 2016 or 2019 farms are affected and patched before closing this item
- Review which accounts, including external and guest accounts, can reach the farm, and limit internet exposure
- Monitor SharePoint servers for unusual requests and unexpected process activity
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – 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-2026-69943 msrc.microsoft.com
- Microsoft Support: SharePoint KB5002927 support.microsoft.com
- Vulners: MSCVE entry for CVE-2026-69943 vulners.com
- Vulnrichment: CVE-2026-69943 (CISA SSVC) vulners.com
- Senserva: KB5002927 details senserva.com
- Stefan Gossner: SharePoint security fixes October 2026 blog.stefan-gossner.com
- OpenCVE: CVE-2026-69943 app.opencve.io
- GitHub issue: CVE-2026-69943 (KEV status) github.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 31 Oct 2026, 19:03.
Original description (NVD)
Improper limitation of a pathname to a restricted directory ('path traversal') in Microsoft Office SharePoint allows an authorized attacker to execute code 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.