Local code execution via use-after-free
Published Jan 13, 2026 · Updated Jan 13, 2026
Use-after-free in Microsoft Office allows local users to execute code through locally accessible Office content processing. Microsoft identifies the memory-lifetime error only as use-after-free and has not disclosed the affected parser, object, file format, or freeing and reuse sequence. No privileges or user interaction are required by the published vector, but execution is local and gains the rights of the Office process.
Summary
What happened
Use-after-free in Microsoft Office allows local users to execute code through locally accessible Office content processing. Microsoft identifies the memory-lifetime error only as use-after-free and has not disclosed the affected parser, object, file format, or freeing and reuse sequence. No privileges or user interaction are required by the published vector, but execution is local and gains the rights of the Office process.
The record
- CVE
- CVE-2026-20953
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Microsoft
- Product
- Microsoft Office LTSC for Mac 2024
- Classifications
- CWE-416, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=16.0.0 <16.105.26011018
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
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
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo