CVE-2025-62563

Local code execution via use-after-free

Published Dec 9, 2025 · Updated Apr 16, 2026

Use-after-free in Microsoft Office Excel allows attackers to execute code locally after a user opens a malicious file. Microsoft has not disclosed the Excel component that frees and later reuses the memory object or the workbook structure that triggers the stale reference. Exploitation requires the user to open the file; Preview Pane viewing is insufficient, and successful code runs with the user's privileges.

CVSS severity7.8
High
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Microsoft Office Excel allows attackers to execute code locally after a user opens a malicious file. Microsoft has not disclosed the Excel component that frees and later reuses the memory object or the workbook structure that triggers the stale reference. Exploitation requires the user to open the file; Preview Pane viewing is insufficient, and successful code runs with the user's privileges.

The record

CVE
CVE-2025-62563
Published
Dec 9, 2025
Updated
Apr 16, 2026
Vendor
Microsoft
Product
Microsoft Office LTSC for Mac 2024
Classifications
CWE-416, T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=-

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office LTSC for Mac 2024version=-
Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Excel 2016version=16.0.0.0 <16.0.5530.1000
Microsoft · Microsoft Office LTSC for Mac 2021version=-
Microsoft · Microsoft Office LTSC 2021version=16.0.1 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office LTSC 2024version=16.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Office Online Serverversion=16.0.0.0 <16.0.10417.20075
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution
T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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