Code execution via use-after-free workbook parsing
Published May 9, 2023 · Updated Jul 10, 2025
Use-after-free in Microsoft Excel allows attackers to execute code by convincing a user to open a maliciously crafted workbook. Excel's workbook-processing code accesses freed memory while parsing attacker-controlled file content; Microsoft has not disclosed the affected function or record type. Exploitation requires user interaction, and successful code executes in the user's security context.
Summary
What happened
Use-after-free in Microsoft Excel allows attackers to execute code by convincing a user to open a maliciously crafted workbook. Excel's workbook-processing code accesses freed memory while parsing attacker-controlled file content; Microsoft has not disclosed the affected function or record type. Exploitation requires user interaction, and successful code executes in the user's security context.
The record
- CVE
- CVE-2023-24953
- Published
- May 9, 2023
- Updated
- Jul 10, 2025
- Vendor
- Microsoft
- Product
- Microsoft Office 2019
- Classifications
- CWE-416, T1204.002, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 9, 2023CVE publishedPublication date reported by the CVE source.
- Jul 10, 2025Record 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=19.0.0 <https://aka.ms/OfficeSecurityReleases
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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