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TI-2026-75021 Aliases CVE-2026-108438

Use after free in Microsoft Office Word leaks information

Priority LOW 30CWE-416Published · Updated

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Microsoft 365 Apps for Enterprise from 16.0.1 is affected until the fix listed by Microsoft, and Microsoft Office 365 for Mac from 1.0.0 before 16.114.26101123, Microsoft Office LTSC for Mac 2021 from 16.0.1 before 16.114.26101123, and Microsoft Office LTSC for Mac 2024 from 16.0.0 before 16.114.26101123 are affected. A use after free flaw in Microsoft Office Word (CWE-416) lets an unauthorized remote attacker disclose information over a network. Exploitation requires user interaction.

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

Description from the CNA

Use after free in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0074 54th percentileScored 2026-11-07
Fix Fixed Microsoft 365 Apps for Enterprise (Microsoft): https://aka.ms/OfficeSecurityReleasesMicrosoft Office 365 for Mac (Microsoft): 16.114.26101123+2 more products

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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 365 for Mac1.0.0 to before 16.114.2610112316.114.26101123Patch availableCNA
MicrosoftMicrosoft Office LTSC for Mac 202116.0.1 to before 16.114.2610112316.114.26101123Patch availableCNA
MicrosoftMicrosoft Office LTSC for Mac 202416.0.0 to before 16.114.2610112316.114.26101123Patch 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 365 for Mac VendorMicrosoft Affected 1.0.0 to before 16.114.26101123 Fixed in 16.114.26101123 Patch available CNA
  • Microsoft Office LTSC for Mac 2021 VendorMicrosoft Affected 16.0.1 to before 16.114.26101123 Fixed in 16.114.26101123 Patch available CNA
  • Microsoft Office LTSC for Mac 2024 VendorMicrosoft Affected 16.0.0 to before 16.114.26101123 Fixed in 16.114.26101123 Patch available CNA

CPE configurations NVD · 5

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:microsoft_365:-:*:*:*:*:macos:*:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:*not specified by NVDVulnerableMicrosoft
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:*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:microsoft_365:-:*:*:*:*:macos:*:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:* Versions not specified by NVD Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:* Versions not specified by NVD Vulnerable ·Microsoft

Remediation

Apply the Microsoft 365 Apps for Enterprise update listed on Microsoft's Office security releases page. Update Microsoft Office 365 for Mac, Microsoft Office LTSC for Mac 2021 and Microsoft Office LTSC for Mac 2024 to version 16.114.26101123.

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 365 for Mac (Microsoft) Fixed in 16.114.26101123
  • Fix · CNA Microsoft Office LTSC for Mac 2021 (Microsoft) Fixed in 16.114.26101123
  • Fix · CNA Microsoft Office LTSC for Mac 2024 (Microsoft) Fixed in 16.114.26101123

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-108438
  2. 2026-10-25 EPSS moved to the 50th–90th percentile

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