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TI-2026-73144 Aliases CVE-2026-97009GHSA-3h57-r5m5-xv5w

Heap-based buffer overflow in Microsoft Excel allows code execution

Priority LOW 36CWE-122Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

Microsoft Office Excel, including Microsoft 365 Apps for Enterprise and Office LTSC 2021 and 2024, contains a heap-based buffer overflow (CWE-122). An unauthorized attacker can execute code locally, and user interaction is required. Microsoft 365 Apps for Enterprise is affected from 16.0.1 before the fixed release, Office LTSC 2021 from 16.0.1 before 16.0.14334.20974, and Office LTSC 2024 from 16.0.0 before 16.0.17932.21056.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00323 25th percentileScored 2026-11-07
Fix Fixed Microsoft 365 Apps for Enterprise (Microsoft): https://aka.ms/OfficeSecurityReleasesMicrosoft Office LTSC 2021 (Microsoft): 16.0.14334.20974+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft 365 Apps for Enterprise16.0.1 to before https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleasesPatch availableCNA
MicrosoftMicrosoft Office LTSC 202116.0.1 to before 16.0.14334.2097416.0.14334.20974Patch availableCNA
MicrosoftMicrosoft Office LTSC 202416.0.0 to before 16.0.17932.2105616.0.17932.21056Patch availableCNA
  • Microsoft 365 Apps for Enterprise VendorMicrosoft Affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
  • Microsoft Office LTSC 2021 VendorMicrosoft Affected 16.0.1 to before 16.0.14334.20974 Fixed in 16.0.14334.20974 Patch available CNA
  • Microsoft Office LTSC 2024 VendorMicrosoft Affected 16.0.0 to before 16.0.17932.21056 Fixed in 16.0.17932.21056 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:*not specified by NVDVulnerableMicrosoft
  • cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:* Versions not specified by NVD Vulnerable ·Microsoft

Remediation

Install the Microsoft 365 Apps for Enterprise release listed in Microsoft's Office security release notes, install Office LTSC 2021 version 16.0.14334.20974 or later, and install Office LTSC 2024 version 16.0.17932.21056 or later.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA Microsoft 365 Apps for Enterprise (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases
  • Fix · CNA Microsoft Office LTSC 2021 (Microsoft) Fixed in 16.0.14334.20974
  • Fix · CNA Microsoft Office LTSC 2024 (Microsoft) Fixed in 16.0.17932.21056

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-97009
  2. 2026-10-13 Alias added: GHSA-3h57-r5m5-xv5w

References

Patch 1

  • TI-2024-14173 Microsoft Outlook Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-09240 Microsoft Outlook Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-25471 Microsoft Project Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2023-17652 Microsoft Outlook Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17368 Microsoft Word Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 7.8
  • TI-2026-17363 Microsoft Office Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 7.8
See all 935 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences