Code execution via out-of-bounds read
Published Jan 13, 2026 · Updated Jan 13, 2026
Out-of-bounds read in Microsoft Office Excel allows local users to execute code when a user opens a crafted file. Microsoft has not disclosed the affected Excel parser, file structure, or memory operation that reads beyond its intended boundary. Exploitation requires user interaction with attacker-controlled content and runs code in the affected user context.
Summary
What happened
Out-of-bounds read in Microsoft Office Excel allows local users to execute code when a user opens a crafted file. Microsoft has not disclosed the affected Excel parser, file structure, or memory operation that reads beyond its intended boundary. Exploitation requires user interaction with attacker-controlled content and runs code in the affected user context.
The record
- CVE
- CVE-2026-20946
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- Microsoft
- Product
- Microsoft Office LTSC for Mac 2024
- Classifications
- CWE-125, T1204.002
- 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
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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.
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Technologies
Your stack
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Your stack
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