CVE-2020-0968Known exploitationPublic exploitNetwork attack vector

Remote code execution via JScript use-after-free

Published Apr 15, 2020 · Updated Oct 21, 2025

Memory corruption in Microsoft Internet Explorer 9 and 11 allows remote attackers to execute code when a user opens crafted content. Published exploit analysis identifies the legacy JScript engine as the locus: CScriptRuntime::Run leaves a VAR::GetValue result outside garbage-collector tracking, letting a second attacker-controlled toString callback free the variant before it is reused. Exploitation runs code with the current user's rights; administrative browser sessions expose the full system.

CVSS severity7.5
High
EPSS probability30.68%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Microsoft Internet Explorer 9 and 11 allows remote attackers to execute code when a user opens crafted content. Published exploit analysis identifies the legacy JScript engine as the locus: CScriptRuntime::Run leaves a VAR::GetValue result outside garbage-collector tracking, letting a second attacker-controlled toString callback free the variant before it is reused. Exploitation runs code with the current user's rights; administrative browser sessions expose the full system.

The record

CVE
CVE-2020-0968
Published
Apr 15, 2020
Updated
Oct 21, 2025
Vendor
Microsoft
Product
Internet Explorer 11
Classifications
CWE-787, T1203, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 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=unspecified
  2. Affected versionversion=Windows 10 for 32-bit Systems
  3. Affected versionversion=Windows 10 for x64-based Systems
  4. Affected versionversion=Windows 10 Version 1607 for 32-bit Systems
  5. Affected versionversion=Windows 10 Version 1607 for x64-based Systems
  6. Affected versionversion=Windows 10 Version 1709 for 32-bit Systems
  7. Affected versionversion=Windows 10 Version 1709 for ARM64-based Systems
  8. Affected versionversion=Windows 10 Version 1709 for x64-based Systems
  9. Affected versionversion=Windows 10 Version 1803 for 32-bit Systems
  10. Affected versionversion=Windows 10 Version 1803 for ARM64-based Systems
  11. Affected versionversion=Windows 10 Version 1803 for x64-based Systems
  12. Affected versionversion=Windows 10 Version 1809 for 32-bit Systems
  13. Affected versionversion=Windows 10 Version 1809 for ARM64-based Systems
  14. Affected versionversion=Windows 10 Version 1809 for x64-based Systems
  15. Affected versionversion=Windows 7 for 32-bit Systems Service Pack 1
  16. Affected versionversion=Windows 7 for x64-based Systems Service Pack 1
  17. Affected versionversion=Windows 8.1 for 32-bit systems
  18. Affected versionversion=Windows 8.1 for x64-based systems
  19. Affected versionversion=Windows RT 8.1
  20. Affected versionversion=Windows Server 2008 R2 for x64-based Systems Service Pack 1
  21. Affected versionversion=Windows Server 2012 R2
  22. Affected versionversion=Windows Server 2016
  23. Affected versionversion=Windows Server 2019

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Internet Explorer 11version=unspecified; version=Windows 10 for 32-bit Systems; version=Windows 10 for x64-based Systems; version=Windows 10 Version 1607 for 32-bit Systems; version=Windows 10 Version 1607 for x64-based Systems; version=Windows 10 Version 1709 for 32-bit Systems; version=Windows 10 Version 1709 for ARM64-based Systems; version=Windows 10 Version 1709 for x64-based Systems; version=Windows 10 Version 1803 for 32-bit Systems; version=Windows 10 Version 1803 for ARM64-based Systems; version=Windows 10 Version 1803 for x64-based Systems; version=Windows 10 Version 1809 for 32-bit Systems; version=Windows 10 Version 1809 for ARM64-based Systems; version=Windows 10 Version 1809 for x64-based Systems; version=Windows 7 for 32-bit Systems Service Pack 1; version=Windows 7 for x64-based Systems Service Pack 1; version=Windows 8.1 for 32-bit systems; version=Windows 8.1 for x64-based systems; version=Windows RT 8.1; version=Windows Server 2008 R2 for x64-based Systems Service Pack 1; version=Windows Server 2012 R2; version=Windows Server 2016; version=Windows Server 2019
Microsoft · Internet Explorer 9version=Windows Server 2008 for 32-bit Systems Service Pack 2; version=Windows Server 2008 for x64-based Systems Service Pack 2

Published CVSS scores

7.6NIST NVDAV:N/AC:H/Au:N/C:C/I:C/A:C
7.5CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:H/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.

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No observations available

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

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution
T1189Drive-by Compromise

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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