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Exchange Server 2019 CU13 Exchange Server 2019 CU13 ESU only Security update
Patch Tuesday

KB5036402

KB5036402: Security update for Exchange Server 2019 CU13, March 2024. Exchange remote-code flaw patched; attachment text extraction removed

In short

A remote-code flaw in Exchange is patched. Text extraction from JPEG, TIFF, and AutoCAD attachments stops for transport rules and DLP scans.

Does it affect you? Applies to: Exchange Server 2019 CU13 x64 servers in organizations enrolled in the Extended Security Update program.

Build
15.2.1258.32
Servicing branch
CU13
Security
1 fixed
Review notes Additional details from the official release notes (5) Read notes
  • Known issues After the March 2024 SU, affected OWA users cannot see inline images or download attachments. Microsoft says to install KB5037224 to fix this issue.
  • Known issues After the March 2024 SU, OwaDeepTestProbe and EacBackEndLogonProbe fail. Microsoft says to install KB5037224 to fix this issue.
  • Known issues After the March 2024 SU, a cached-mode Outlook search shows the server-results error. Microsoft says to install KB5037224 to fix this issue.
  • Known issues After the March 2024 SU, users cannot preview Word documents in OWA and receive an error. Microsoft says to install KB5037224 to fix this issue.
  • Known issues Microsoft says KB5037224, released April 23, 2024, fixes the Download Domains, probe, Outlook cached-mode search, and OWA Word-preview issues.

The official sources are linked at the end of the page.

For servers running Cumulative Update 13: each cumulative update gets its own update. Support for this version ended on October 14, 2025: Microsoft releases this update only to organizations enrolled in the Extended Security Update (ESU) program, not through Microsoft Update. The others should move to Exchange Server Subscription Edition. Which version am I on?

What changes

Fix 1 change

EWS

  • EWS search requests no longer return inaccurate results.1

Removal 1 change

Attachment text extraction

For: Organizations using transport rules or DLP to inspect attachments

  • Exchange no longer extracts text from JPEG, TIFF, or AutoCAD attachments for transport rules and DLP scans.2
    The March 2024 security update disables Oracle Outside In Technology (OIT), also known as OutsideInModule. The change affects attachment text extraction in Exchange Transport Rules and Data Loss Prevention rules.

Known issues

  1. Open Affects: Organizations and IT administrators

    After you install this security update (SU), the program no longer supports the Oracle Outside In Technology (OIT) or OutsideInModule.

    After installation, Exchange no longer extracts text from JPEG, TIFF, or AutoCAD attachments for transport rules and DLP scans.3

    How to apply the workaround PowerShell

    Administrators can use Microsoft's PowerShell script to override the setting that disables OIT. Only consider this if a functional issue affects your organization's mail flow.3

  2. Open Affects: Organizations and IT administrators

    After you install this SU, Download Domains are no longer working as expected.

    Download Domains might not work as expected. Some Outlook users might not see inline images or download attachments in Outlook on the web.4

    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.

  3. Open Affects: Organizations and IT administrators

    After you install this SU, OwaDeepTestProbe and EacBackEndLogonProbe are no longer working.

    The OwaDeepTestProbe and EacBackEndLogonProbe might stop working after installation.5

    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.

  4. Open Affects: Organizations and IT administrators

    After you install this SU, you receive a "We're having trouble fetching results from the server" error message when you run a search in Microsoft Outlook cached mode.

    Searching in Microsoft Outlook cached mode might show “We're having trouble fetching results from the server.”6

    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.

  5. Open Affects: Organizations and IT administrators

    After you install this SU, you can't preview Microsoft Word documents in Outlook on the web (OWA), and you receive an error message.

    Word documents might not open in Outlook on the web's preview, and an error message might appear.7

    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.

Technical details

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

Data sheet

Released
2024-03-12
Classification
Security Updates
Type
Cumulative update
Servicing branch
CU13
Replaced by
KB5037224
VersionBuildChannel
2019 15.2.1258.32 General availability

Security

1 vulnerability fixed
1 not rated
VulnerabilitySeverityCVSS
CVE-2024-26198
Microsoft Exchange Server Remote Code Execution Vulnerability
 Not rated —

Sources

Updated
Cited passages from Microsoft's official notes (7)
  1. 1. EWS search request displays inaccurate results support.microsoft.com
  2. 2. Starting in the Microsoft Exchange Server March 2024 security update, Exchange Server no longer uses “Oracle Outside In Technology” (also known as OutsideInModule or OIT) to perform text extraction workloads when it processes email messages in transport if those messages contain attachments. support.microsoft.com
  3. 3. Microsoft is providing a PowerShell script for administrators to use if they want to override the default setting that disables OIT. support.microsoft.com
  4. 4. After you install this SU, Download Domains are no longer working as expected. support.microsoft.com
  5. 5. After you install this SU, OwaDeepTestProbe and EacBackEndLogonProbe are no longer working. support.microsoft.com
  6. 6. After you install this SU, you receive a "We're having trouble fetching results from the server" error message when you run a search in Microsoft Outlook cached mode. support.microsoft.com
  7. 7. After you install this SU, you can't preview Microsoft Word documents in Outlook on the web (OWA), and you receive an error message. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 7 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: not passed

A second AI read the text against the sources: correctness 3/5, clarity 3/5, completeness 4/5. 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