CVE-2026-40360: Microsoft Excel Information Disclosure Vulnerability

Published May 12, 2026
·
Updated

Microsoft Excel Information Disclosure Vulnerability

Other sources

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.

Microsoft

Affected Software

38 affected componentsFixes available
Microsoft Excel
Microsoft Excel 2016
Microsoft Office LTSC for Mac 2024
Microsoft Excel 2016
Microsoft Office LTSC for Mac 2021
Microsoft Office 2019 for 64-bit editions
Microsoft Office LTSC 2024 for 64-bit editions
Microsoft 365 Apps for Enterprise
Microsoft Office LTSC 2021 for 64-bit editions
Microsoft 365 Apps for Enterprise
Microsoft Office LTSC 2024 for 32-bit editions
Microsoft Office LTSC 2021 for 32-bit editions
Microsoft 365 Apps
Microsoft 365 Apps
Microsoft Excel=2016
Microsoft Excel=2016
Microsoft Office=2019
Microsoft Office=2019
Microsoft Office Long Term Servicing Channel=2021
Microsoft Office Long Term Servicing Channel=2021
Microsoft Office Long Term Servicing Channel Macos=2021
Microsoft Office Long Term Servicing Channel=2024
Microsoft Office Long Term Servicing Channel=2024
Microsoft Office Long Term Servicing Channel Macos=2024
Microsoft Office Online Server<16.0.10417.20128
Microsoft Excel 2016<16.0.5552.1000
16.0.5552.1000
Microsoft Office LTSC for Mac 2024<16.109.26051019
16.109.26051019
Microsoft Office LTSC 2024 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Excel 2016<16.0.5552.1000
16.0.5552.1000
Microsoft Office LTSC 2024 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2021 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC 2021 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office LTSC for Mac 2021<16.109.26051019
16.109.26051019
Microsoft Office 2019 for 32-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office 2019 for 64-bit editions<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft 365 Apps for Enterprise<https://aka.ms/OfficeSecurityReleases
https://aka.ms/OfficeSecurityReleases
Microsoft Office Online Server<16.0.10417.20128
16.0.10417.20128

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.0.5552.1000Patch KB5002865
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.109.26051019
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in https://aka.ms/OfficeSecurityReleases
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 16.0.10417.20128Patch KB5002871

Event History

May 12, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·04:58 PM
Data Sourced
via MITRE·04:58 PM
DescriptionSeverity
Data Sourced
via NVD·06:17 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-40360?

The severity of CVE-2026-40360 is classified as moderate due to its potential for information disclosure.

2

How do I fix CVE-2026-40360?

To fix CVE-2026-40360, update your affected Microsoft Excel version to the latest security patch.

3

What products are affected by CVE-2026-40360?

CVE-2026-40360 affects several versions of Microsoft Excel, including Office LTSC and Excel 2016.

4

Can CVE-2026-40360 lead to data breaches?

Yes, CVE-2026-40360 could potentially lead to data breaches by allowing unauthorized information disclosure.

5

Is CVE-2026-40360 a critical vulnerability?

CVE-2026-40360 is not classified as critical but still poses significant risks to affected systems.

Contact

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