CVE-2026-20944: Microsoft Word Remote Code Execution Vulnerability

Overview

Severity
High (CVSS 8.4)
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
Category
Remote Code Execution
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Jan
Released
2026-01-13
EPSS Score
0.03% (percentile: 8.9%)

Description

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

FAQ

According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution? The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. This means an attacker or victim needs to execute code from the local machine to exploit the vulnerability. According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do? An attacker must send a user a malicious Office file and convince them to open it. Is the Preview Pane an attack vector for this vulnerability? Yes, the Preview Pane is an attack vector.

Affected Products (4)

Microsoft Office

  • Microsoft 365 Apps for Enterprise for 32-bit Systems
  • Microsoft 365 Apps for Enterprise for 64-bit Systems
  • Microsoft Office LTSC for Mac 2021
  • Microsoft Office LTSC for Mac 2024

Security Updates (1)

Acknowledgments

Mose Nilsson

Revision History

  • 2026-01-13: Information published.