Code execution via heap buffer overflow
Published May 13, 2025 · Updated Feb 13, 2026
Heap-based buffer overflow in Microsoft Office Excel allows attackers to execute code locally when a user opens a crafted file. Excel performs out-of-bounds heap reads and writes while processing the file, but Microsoft has not disclosed the affected parser or file structure. Exploitation requires user interaction and runs attacker-controlled code with the user's privileges, allowing data access, modification, and service interruption.
Summary
What happened
Heap-based buffer overflow in Microsoft Office Excel allows attackers to execute code locally when a user opens a crafted file. Excel performs out-of-bounds heap reads and writes while processing the file, but Microsoft has not disclosed the affected parser or file structure. Exploitation requires user interaction and runs attacker-controlled code with the user's privileges, allowing data access, modification, and service interruption.
The record
- CVE
- CVE-2025-30376
- Published
- May 13, 2025
- Updated
- Feb 13, 2026
- Vendor
- Microsoft
- Product
- Microsoft Office LTSC for Mac 2024
- Classifications
- CWE-787, CWE-125, CWE-122, T1204.002, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 13, 2025CVE publishedPublication date reported by the CVE source.
- Feb 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 <16.97.25042725
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.
Weakness, pattern, technique
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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