CVE-2023-33161

Code execution via double-free memory corruption

Published Jul 11, 2023 · Updated Feb 28, 2025

Double-free memory corruption in Microsoft Excel in affected Office releases allows local attackers to execute code via a crafted file. Microsoft identifies the weakness as a double free but has not disclosed the affected parser, object lifetime, or exact unsafe operation. Exploitation requires a user to open the file, after which attacker-controlled code runs with that user's privileges.

CVSS severity7.8
High
EPSS probability0.63%
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 in affected Office releases allows local attackers to execute code via a crafted file. Microsoft identifies the weakness as a double free but has not disclosed the affected parser, object lifetime, or exact unsafe operation. Exploitation requires a user to open the file, after which attacker-controlled code runs with that user's privileges.

The record

CVE
CVE-2023-33161
Published
Jul 11, 2023
Updated
Feb 28, 2025
Vendor
Microsoft
Product
Microsoft Office LTSC for Mac 2021
Classifications
CWE-415, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 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

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Is a vulnerable build present?

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

  1. Affected versionversion=16.0.1 <16.75.23070901

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office LTSC for Mac 2021version=16.0.1 <16.75.23070901
Microsoft · Microsoft Office 2019 for Macversion=16.0.0 <16.75.23070901
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

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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