KB5002564: Cumulative update for SharePoint Server, version SE, March 2024. Remote-code flaw fixed; farm joins may fail after the update

Fixes an Important SharePoint Server remote-code execution vulnerability and adds the Version 24H1 feature update. It also introduces a Microsoft.Owin change that requires a SharePoint upgrade action before sites can be browsed.

Does it affect you? Applies to: SharePoint Server Subscription Edition devices with the release version installed. The update package is for x64.

What changes

Fixes 6 changes

Modern List web part

The modern List web part no longer freezes when you select See all for a grouped view if the site URL contains an apostrophe.¹

List item editing pane

For: Users of right-to-left languages

In right-to-left languages, the Edit button no longer overlaps the multiline field title in the list item editing pane.²

Communication site navigation

Horizontal navigation on a communication site reflects the current site correctly.³

SharePoint site themes

Customizing a SharePoint site theme no longer delays the login form by five seconds while it loads.⁴

Quick edit mode

Plain text is no longer rendered as a hyperlink in quick edit mode.⁵

Classic UI

The classic UI shows the correct status of a subsite.⁶

Improvement 1 change

Content Security Policy

For: SharePoint farm administrators

Farm administrators can disable SharePoint's Content Security Policy HTTP header in SharePoint Pages.⁷
Set $farm.EnableCSPHeaderForPage = $false and run $farm.Update().

New feature 1 change

SharePoint Server Subscription Edition

For: SharePoint Server users and administrators

The Version 24H1 feature update is included, and future public updates will include it too.⁸

Known issues

Open Affects: Organizations and IT administrators

After you install this security update, you may encounter an issue in which servers cannot join an existing SharePoint farm.

After installing this update, servers might be unable to join an existing SharePoint farm.⁹

Workaround status No workaround yet

Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.
Open Affects: Organizations and IT administrators

This security update also introduces a newer version of the Microsoft.Owin component.

If the SharePoint upgrade action is not run after installation, browsing SharePoint sites can produce a Microsoft.Owin assembly-load error.¹⁰

How to apply the workaround SharePoint Management Shell

The upgrade action registers the new Microsoft.Owin component version in SharePoint Server's Web.config files.¹⁰
Step-by-step instructions, command & download kit
2 steps SharePoint Management Shell Instructions (.txt)

Show steps & kit Hide steps & kit
Step-by-step procedure
1. After installing the update, open SharePoint Management Shell and run the upgrade commands.
2. Run the upgrade during a maintenance window when downtime is acceptable.
SharePoint Management Shell

> Initialize-SPResourceSecurity> Install-SPService> Install-SPFeature -AllExistingFeatures> Install-SPApplicationContent> Upgrade-SPFarm

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released: 2024-03-12
Classification: Security Updates
Type: Cumulative update
Restart: Required
Replaces: KB5002540
Replaced by: KB5002581

Version	Build	Channel
SE	16.0.17328.20136	General availability

Security

1 vulnerability fixed

1 important

Vulnerability	Severity	CVSS
CVE-2024-21426 Microsoft SharePoint Server Remote Code Execution Vulnerability	Important	7.8

Downloads (Microsoft Update Catalog)

Package SE

1.5 GB

sts-x-none.cab Main update · KB5002564 SHA-1: b0845b9d…d721c6

Language packs (49)

Sources

Updated Oct 27, 2026

Cited passages from Microsoft's official notes (10)

1. Fixes an issue in which the modern List web part freezes when you select the See all link for a grouped view if the site URL contains the apostrophe (') character. support.microsoft.com
2. Fixes an issue in which the Edit button overlaps the multiline field title in the list item editing pane when you use right-to-left (RTL) languages. support.microsoft.com
3. Fixes an issue in which horizontal navigation of the communication site doesn't reflect the current site correctly. support.microsoft.com
4. Fixes an issue in which SharePoint site theme customization delays the login form by 5 seconds while the form tries to load. support.microsoft.com
5. Fixes an issue in which plain text will be rendered as a hyperlink in quick edit mode. support.microsoft.com
6. Fixes an issue in which the classic UI doesn't show the correct status of a subsite. support.microsoft.com
7. Allows users to disable SharePoint's Content Security Policy (CSP) HTTP header in SharePoint Pages. support.microsoft.com
8. This security update introduces the SharePoint Server Subscription Edition Version 24H1 feature update. This feature update will be included in all SharePoint Server Subscription Edition public updates going forward. support.microsoft.com
9. After you install this security update, you may encounter an issue in which servers cannot join an existing SharePoint farm. support.microsoft.com
10. Initialize-SPResourceSecurity Install-SPService Install-SPFeature -AllExistingFeatures Install-SPApplicationContent Upgrade-SPFarm support.microsoft.com

Checked automatically: 8 of 8 checks passed, 10 quoted passages · compared with Microsoft's page on Oct 20, 2026

Quotes found in the official pages: passed
Numbers found in the sources: passed
Vulnerabilities from the dossier only: passed
Links to allowed domains only: passed
Every official change covered: passed
Readable plain text: passed
Changes confirmed by the file list: passed
Sources agree: passed

A second AI read the text against the sources: correctness 4/5, clarity 5/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake