Microsoft Office SharePoint Remote Code Execution Vulnerability
Published · updated 17 sep 2026
What does this mean?
- Remote Code Execution. An attacker can run their own code on the system remotely. This is the most serious type: it can lead to taking over the system.
- It can be exploited over the network (including from the internet if the service is reachable there), with an ordinary user account and without any user action.
- CVSS 8.8 out of 10: high. Microsoft rates it Important.
- No attacks reported; Microsoft expects exploitation to be less likely.
- What should you do? Install the security update for the version you run (or a later cumulative update):
- Microsoft SharePoint Server Subscription Edition: KB5002908
16.0.20326.20090
- Microsoft SharePoint Server Subscription Edition: KB5002908
- This applies to SharePoint Server you run yourself. Microsoft updates SharePoint Online in Microsoft 365.
Missing authorization in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
SharePoint Office / Microsoft 365 Apps
How do I check if I am affected?
SharePoint Server: check and update
- Check your farm build in the SharePoint Management Shell:
Or in Central Administration → Upgrade and Migration → Check product and patch installation status.(Get-SPFarm).BuildVersion - If the build is equal to or higher than the build under "Affected products and updates" below, this vulnerability is fixed. A later cumulative update includes the fix too.
- Otherwise install the update on every server in the farm, then run the SharePoint Products Configuration Wizard, or:
PSConfig.exe -cmd upgrade -inplace b2b -wait -cmd applicationcontent -install -cmd installfeatures -cmd secureresources -cmd services -install - You do not need to update SharePoint Online in Microsoft 365; Microsoft does that.
What kind of flaw is this?
- CWE-862: Missing Authorization
An action is missing the check whether the user may perform it.
Key facts
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CCVSS metrics
| Base score metrics | |
|---|---|
| Attack Vector | Network |
| Attack Complexity | Low |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity | High |
| Availability | High |
| Temporal score metrics | |
| Exploit Code Maturity | Unproven |
| Remediation Level | Official Fix |
| Report Confidence | Confirmed |
Affected products and updates
| Product | Update | Build |
|---|---|---|
| Microsoft SharePoint Server Subscription Edition | KB5002908 · Security Update | 16.0.20326.20090 |
FAQ
- How could an attacker exploit the vulnerability?
- In a network-based attack, an authenticated attacker with Manage List permissions could execute code remotely on the SharePoint Server.
Revisions
| Version | Date | Note |
|---|---|---|
| 1.1 | 17 sep 2026 | Updated an acknowledgement. This is an informational change only. |
| 1 | 8 sep 2026 | Information published. |
This is in the weekly digest for week 38 · What changed this week? →
View at Microsoft → ← All security advisories
Source: Microsoft Security Update Guide. 365Fanatic is not affiliated with Microsoft.