CVE-2023-33137Public exploit

Code execution via crafted spreadsheet double-free

Published Jun 13, 2023 · Updated Feb 28, 2025

Double-free memory corruption in Microsoft Excel products allows remote attackers to execute code when a user opens a crafted spreadsheet file. Microsoft identifies CWE-415 but has not disclosed the affected parser, function, or document field that causes the same allocation to be freed twice. Exploitation requires user interaction with the malicious file, and successful code runs in the context of that user.

CVSS severity7.8
High
EPSS probability2.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double-free memory corruption in Microsoft Excel products allows remote attackers to execute code when a user opens a crafted spreadsheet file. Microsoft identifies CWE-415 but has not disclosed the affected parser, function, or document field that causes the same allocation to be freed twice. Exploitation requires user interaction with the malicious file, and successful code runs in the context of that user.

The record

CVE
CVE-2023-33137
Published
Jun 13, 2023
Updated
Feb 28, 2025
Vendor
Microsoft
Product
Microsoft Office 2019
Classifications
CWE-415, T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 13, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=19.0.0 <https://aka.ms/OfficeSecurityReleases

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Excel 2016version=16.0.0.0 <16.0.5400.1000
Microsoft · Microsoft Excel 2013version=15.0.0.0 <15.0.5563.1000
Microsoft · Microsoft Office Online Serverversion=16.0.1 <16.0.10399.20000

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-415Double Free
T1203Exploitation for Client Execution
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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