Microsoft Office SharePoint Remote Code Execution Vulnerability
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.
Summary
Heap-based buffer overflow (CWE-122) in Microsoft Office SharePoint allows an authorized attacker to execute code over a network. The CVSS 3.1 base score is 8.8 (HIGH). CISA has not added the flaw to its Known Exploited Vulnerabilities catalog, and its SSVC assessment reports no exploitation, no automatable attack and total technical impact.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
Heap-based buffer overflow in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 to before 16.0.20326.20190 | 16.0.20326.20190 | Patch available | CNA |
- Microsoft SharePoint Server Subscription Edition VendorMicrosoft Affected 16.0.0 to before 16.0.20326.20190 Fixed in 16.0.20326.20190 Patch available CNA
Remediation
Microsoft SharePoint Server Subscription Edition versions from 16.0.0 before 16.0.20326.20190 are affected. Update to 16.0.20326.20190 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Microsoft SharePoint Server Subscription Edition (Microsoft) Fixed in 16.0.20326.20190
Timeline
- 2026-10-13 Threatist record created from CVE-2026-88155
- 2026-10-13 Alias added: GHSA-77gw-4c87-g3xj
- 2026-10-14 Priority changed: LOW → MEDIUM
References
More Microsoft Sharepoint Server vulnerabilities
- TI-2026-42212 Microsoft SharePoint Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2026-37256 Microsoft SharePoint Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2026-16982 Microsoft SharePoint Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2025-33671 Microsoft SharePoint Server Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2023-13749 Microsoft SharePoint Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2019-00394 Improper input validation in Microsoft SharePoint Server KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-88155 · CVE Program
- CVE-2026-88155 · NVD
- FIRST EPSS
- GHSA-77gw-4c87-g3xj · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences