Microsoft Security Update Guide · Office / Microsoft 365 Apps
Microsoft Office Click-To-Run Elevation of Privilege Vulnerability
Published
What does this mean?
- Elevation of Privilege. An attacker can gain more rights than they should have, for example admin rights.
- It can be exploited with access to the device itself, with an ordinary user account and without any user action.
- CVSS 7.8 out of 10: high. Microsoft rates it Important.
- No attacks reported; Microsoft expects exploitation to be less likely.
- What should you do? Install the security update for the version you run (or a later cumulative update):
- Microsoft 365 Apps for Enterprise for 64-bit Systems: KBRelease Notes
https://aka.ms/OfficeSecurityReleases - Microsoft 365 Apps for Enterprise for 32-bit Systems: KBRelease Notes
https://aka.ms/OfficeSecurityReleases - Microsoft Office LTSC 2024 for 64-bit editions: KBRelease Notes
16.0.17932.21056 - Microsoft Office LTSC 2024 for 32-bit editions: KBRelease Notes
16.0.17932.21056 - Microsoft Office LTSC 2021 for 32-bit editions: KBRelease Notes
16.0.14334.20974 - Microsoft Office LTSC 2021 for 64-bit editions: KBRelease Notes
16.0.14334.20974
- Microsoft 365 Apps for Enterprise for 64-bit Systems: KBRelease Notes
Use after free in Microsoft Office Click-To-Run allows an authorized attacker to elevate privileges locally.
What kind of flaw is this?
- CWE-416: Use After Free
The program uses memory after it was freed (use after free), which can lead to running code.
Key facts
Released
13 okt 2026
Impact
Elevation of Privilege
Max severity
Important
Weakness
CVSS 3.1
7.8 / 6.8 (base / temporal)
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CPublicly disclosed
No
Exploited
No
Exploitability assessment
Exploitation Unlikely
Customer action required
Yes
Links
CVSS metrics
| Base score metrics | |
|---|---|
| Attack Vector | Local |
| Attack Complexity | Low |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity | High |
| Availability | High |
| Temporal score metrics | |
| Exploit Code Maturity | Unproven |
| Remediation Level | Official Fix |
| Report Confidence | Confirmed |
Affected products and updates
| Product | Update | Build |
|---|---|---|
| Microsoft 365 Apps for Enterprise for 64-bit Systems | KBRelease Notes | https://aka.ms/OfficeSecurityReleases |
| Microsoft 365 Apps for Enterprise for 32-bit Systems | KBRelease Notes | https://aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2024 for 64-bit editions | KBRelease Notes | 16.0.17932.21056 |
| Microsoft Office LTSC 2024 for 32-bit editions | KBRelease Notes | 16.0.17932.21056 |
| Microsoft Office LTSC 2021 for 32-bit editions | KBRelease Notes | 16.0.14334.20974 |
| Microsoft Office LTSC 2021 for 64-bit editions | KBRelease Notes | 16.0.14334.20974 |
FAQ
- What privileges could be gained by an attacker who successfully exploited this vulnerability?
- An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.
Revisions
| Version | Date | Note |
|---|---|---|
| 1 | 13 okt 2026 | Information published. |
This is in the weekly digest for week 42: everything that changed in Microsoft 365 this week. →
View at Microsoft → ← All security advisories
Source: Microsoft Security Update Guide. 365Fanatic is not affiliated with Microsoft.
