Code execution via out-of-bounds read
Published Sep 8, 2026 · Updated Sep 9, 2026
An out-of-bounds read in Microsoft Office Excel allows remote attackers to execute code after a user opens crafted content. Microsoft has not disclosed the affected file parser, data structure, or specific bounds-checking error that causes the read beyond allocated memory. Exploitation requires user interaction and can run attacker-controlled code in the affected user's Office context.
Summary
What happened
An out-of-bounds read in Microsoft Office Excel allows remote attackers to execute code after a user opens crafted content. Microsoft has not disclosed the affected file parser, data structure, or specific bounds-checking error that causes the read beyond allocated memory. Exploitation requires user interaction and can run attacker-controlled code in the affected user's Office context.
The record
- CVE
- CVE-2026-78518
- Published
- Sep 8, 2026
- Updated
- Sep 9, 2026
- Vendor
- Microsoft
- Product
- Microsoft Office LTSC for Mac 2024
- Classifications
- CWE-20, CWE-125, T1204.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 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?
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- Affected versionversion=-
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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