CVE-2026-40366 PUBLISHED

Microsoft Word Remote Code Execution Vulnerability

Assigner: microsoft
Reserved: 11.04.2026 Published: 12.05.2026 Updated: 13.05.2026

Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CVSS Score: 8.4

Product Status

Vendor Microsoft
Product Microsoft 365 Apps for Enterprise
Versions
  • affected from 16.0.1 to https://aka.ms/OfficeSecurityReleases (excl.)
Vendor Microsoft
Product Microsoft Office 2019
Versions
  • affected from 19.0.0 to https://aka.ms/OfficeSecurityReleases (excl.)
Vendor Microsoft
Product Microsoft Office LTSC 2021
Versions
  • affected from 16.0.1 to https://aka.ms/OfficeSecurityReleases (excl.)
Vendor Microsoft
Product Microsoft Office LTSC 2024
Versions
  • affected from 16.0.0 to https://aka.ms/OfficeSecurityReleases (excl.)
Vendor Microsoft
Product Microsoft Office LTSC for Mac 2021
Versions
  • affected from 16.0.1 to 16.109.26051019 (excl.)
Vendor Microsoft
Product Microsoft Office LTSC for Mac 2024
Versions
  • affected from 16.0.0 to 16.109.26051019 (excl.)
Vendor Microsoft
Product Microsoft Word 2016
Versions
  • affected from 16.0.1 to 16.0.5552.1000 (excl.)

References

Problem Types