Local code execution via integer underflow
Published Jun 9, 2026 · Updated Jun 9, 2026
Integer underflow in Microsoft Office Excel allows attackers to execute code locally after a victim opens a crafted workbook. Microsoft has not disclosed the affected workbook parser or the operation that truncates a numeric value and produces a use-after-free condition. Exploitation requires user interaction, and successful code runs with the victim's privileges on affected Windows or macOS installations.
Summary
What happened
Integer underflow in Microsoft Office Excel allows attackers to execute code locally after a victim opens a crafted workbook. Microsoft has not disclosed the affected workbook parser or the operation that truncates a numeric value and produces a use-after-free condition. Exploitation requires user interaction, and successful code runs with the victim's privileges on affected Windows or macOS installations.
The record
- CVE
- CVE-2026-44823
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Microsoft Office LTSC for Mac 2024
- Classifications
- CWE-416, CWE-197, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
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Your stack
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