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Microsoft Security Update Guide · SharePoint

Microsoft Office SharePoint Remote Code Execution Vulnerability

Microsoft · EN CVE-2026-69282 Important Action required CVSS 8.8 Updated

Published 8 sep 2026 · updated 24 sep 2026

Summary Detailed Security

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
This applies to SharePoint Server you run yourself. Microsoft updates SharePoint Online in Microsoft 365.

Microsoft Office SharePoint · Remote Code Execution

Improper access control 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:
```
(Get-SPFarm).BuildVersion
```
Or in Central Administration → Upgrade and Migration → Check product and patch installation status.
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-284: Improper Access Control
Access to a function or data is not properly restricted.

Key facts

Released

8 sep 2026

Last revised

24 sep 2026 (v2)

Impact

Remote Code Execution

Max severity

Important

Weakness

CWE-284: Improper Access Control

CVSS 3.1

8.8 / 7.7 (base / temporal)

Vector string

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

Publicly disclosed

Exploited

Exploitability assessment

Exploitation Less Likely

Customer action required

Yes

Links

Microsoft Security Update Guide · CVE.org

CVSS 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

I am running SharePoint Server 2016. Do the updates for SharePoint Enterprise Server 2016 also apply to the version I am running?: Yes. The same KB number applies to both SharePoint Server 2016 and SharePoint Enterprise Server 2016. Customers running either version should install the security update to be protected from this vulnerability.
How could an attacker exploit this vulnerability?: An authenticated attacker with low-level, list-level permissions on a SharePoint site could submit a specially crafted event receiver definition that causes the server to load an attacker-specified code library and construct an attacker-specified type before the server has verified that the caller is authorized to do so. Successful exploitation could allow the attacker to execute code on the SharePoint server. Network access and authentication are required; user interaction is not required.
There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software?: Yes. Customers should apply all updates offered for the software installed on their systems. If multiple updates apply, they can be installed in any order.

Revisions

Version	Date	Note
2	24 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 39 · What changed this week? →

View at Microsoft → ← All security advisories

Source: Microsoft Security Update Guide. 365Fanatic is not affiliated with Microsoft.