CVE-2021-41368

Code execution via ACCDB object use-after-free

Published Nov 10, 2021 · Updated Aug 19, 2026

Use-after-free in Microsoft Access in affected Office releases allows remote attackers to execute code through a crafted ACCDB database file. The ACCDB parser fails to verify that an object exists before operating on it, leaving a freed object available for subsequent use. Exploitation requires the target to visit a malicious page or open the file, after which code runs in the current Access process.

CVSS severity7.8
High
EPSS probability4.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Microsoft Access in affected Office releases allows remote attackers to execute code through a crafted ACCDB database file. The ACCDB parser fails to verify that an object exists before operating on it, leaving a freed object available for subsequent use. Exploitation requires the target to visit a malicious page or open the file, after which code runs in the current Access process.

The record

CVE
CVE-2021-41368
Published
Nov 10, 2021
Updated
Aug 19, 2026
Vendor
Microsoft
Product
Microsoft Office 2016
Classifications
T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 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.

  1. Affected versionversion=16.0.0 <16.0.5239.1001

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office 2016version=16.0.0 <16.0.5239.1001
Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office 2013version=15.0.0 <15.0.5397.1001
Microsoft · Microsoft Office LTSC 2021version=16.0.1 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.1MicrosoftCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N/E:U/RL:O/RC:C
6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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

T1203Exploitation for Client Execution
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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