CVE-2020-0906Network attack vector

Code execution via freed-pointer reuse in spreadsheets

Published Apr 15, 2020 · Updated Aug 4, 2024

Use-after-free in Microsoft Excel allows remote attackers to execute arbitrary code by convincing a user to open a crafted XLS file. Excel reuses a pointer after crafted XLS data frees it; related crafted OLE streams in XLSM files expose memory through the same freed-pointer pattern. Exploitation requires user interaction and runs code in the current Excel process; the XLSM path alone provides only information disclosure unless chained with another flaw.

CVSS severity8.8
High
EPSS probability11.54%
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 Excel allows remote attackers to execute arbitrary code by convincing a user to open a crafted XLS file. Excel reuses a pointer after crafted XLS data frees it; related crafted OLE streams in XLSM files expose memory through the same freed-pointer pattern. Exploitation requires user interaction and runs code in the current Excel process; the XLSM path alone provides only information disclosure unless chained with another flaw.

The record

CVE
CVE-2020-0906
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Microsoft Office
Classifications
T1203, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=2010 Service Pack 2 (32-bit editions)
  2. Affected versionversion=2010 Service Pack 2 (64-bit editions)
  3. Affected versionversion=2013 RT Service Pack 1
  4. Affected versionversion=2013 Service Pack 1 (32-bit editions)
  5. Affected versionversion=2013 Service Pack 1 (64-bit editions)
  6. Affected versionversion=2016 (32-bit edition)
  7. Affected versionversion=2016 (64-bit edition)
  8. Affected versionversion=2019 for 32-bit editions
  9. Affected versionversion=2019 for 64-bit editions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Officeversion=2010 Service Pack 2 (32-bit editions); version=2010 Service Pack 2 (64-bit editions); version=2013 RT Service Pack 1; version=2013 Service Pack 1 (32-bit editions); version=2013 Service Pack 1 (64-bit editions); version=2016 (32-bit edition); version=2016 (64-bit edition); version=2019 for 32-bit editions; version=2019 for 64-bit editions
Microsoft · Microsoft Excelversion=2010 Service Pack 2 (32-bit editions); version=2010 Service Pack 2 (64-bit editions); version=2013 RT Service Pack 1; version=2013 Service Pack 1 (32-bit editions); version=2013 Service Pack 1 (64-bit editions); version=2016 (32-bit edition); version=2016 (64-bit edition)
Microsoft · Microsoft 365 Apps for enterpriseversion=32-bit Systems; version=64-bit Systems

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
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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