Critical CVSS 8.4 EPSS 0.00486 2026-01 archive

Executive Summary

Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to execute code locally.

Overview

8.4
CVSS HIGH
Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released Jan 13 2026
Last Updated Jan 13 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.00486 — 0.37938 percentile
NVD CVSS 8.4 HIGH — matches MSRC

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
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.3

EPSS Score

0.00486
probability of exploitation in the next 30 days
0.37938 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

4 affected products
Product KB Article Severity Impact Restart Required
Microsoft 365 Apps for Enterprise for 32-bit Systems Click to Run (Security Update) Critical Remote Code Execution No
Microsoft 365 Apps for Enterprise for 64-bit Systems Click to Run (Security Update) Critical Remote Code Execution No
Microsoft Office LTSC for Mac 2021 Release Notes (Security Update) Critical Remote Code Execution Maybe
Microsoft Office LTSC for Mac 2024 Release Notes (Security Update) Critical Remote Code Execution Maybe

Patches

2 patches
Article Type Restart
Click to Run Security Update No
Release Notes Security Update Maybe

Known Exploits

Acknowledgments

Mose Nilsson