CVE-2026-109502: Microsoft Office SharePoint Elevation of Privilege Vulnerability
CVE-2026-109502 is an elevation of privilege vulnerability in Microsoft Office SharePoint, rated Important by Microsoft, with a CVSS 3.1 base score of 8.8 (High). An attacker can exploit it remotely over the network, with low privileges and without user interaction. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday, delivered through 1 security update (KB5002945). It affects 1 product in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2026-109502
- Severity
- High CVSS 8.8
- Microsoft severity
- Important
- Impact
- Elevation of Privilege
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2026-109502 at 8.8 (temporal 7.7) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Server-side request forgery (ssrf) in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.
Frequently asked questions (Microsoft)
Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.
How could an attacker exploit this vulnerability?
An authenticated attacker with permission to edit business data connection metadata could send a specially crafted request that exposes authentication information for the privileged SharePoint farm service account. The exposed information could allow the attacker to act with that account's privileges. User interaction is not required.
Affected products (1)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft SharePoint Server Subscription Edition | KB5002945 | Security Update | 16.0.20326.20278 |
Security updates (1)
- KB5002945 (Security Update)
Acknowledgments
- Cassio Lima
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |