Background exploitation KEV catalog
CVE-2020-1380

Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the…

CheckOps priority index
5.6/10 Patch within 7 days
Severity7.8
Probability2.4
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 24.2% higher than 97.9% of CVEs
CVSS 3.1 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:
Exploited for 1,827 days 03 Nov 2021
CISA due date 03 May 2022 for US federal agencies

Exploitation probability EPSS · FIRST

05010026 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)03 Nov 2021
  • Exploited in EUVD (ENISA)03 Nov 2021
  • Used by ransomwareno
  • EPSS above 10 %24.2%
  • No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked "safe for initialization" in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability. The security update addresses the vulnerability by modifying how the scripting engine handles objects in memory.

Affected products

Internet Explorer 11Internet Explorer
Affected versions
  • 1.0.0 <publication
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 24.2%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2026-96951Microsoft Windows Command Injection Vulnerability
    5.6 · Actively exploited
  • CVE-2026-65660Microsoft SharePoint Code Injection Vulnerability
    5.0 · Actively exploited
  • CVE-2026-85880Microsoft Windows Heap-Based Buffer Overflow Vulnerability
    4.3 · Actively exploited
  • CVE-2026-81963Microsoft Windows Link Following Vulnerability
    4.3 · Actively exploited
  • CVE-2019-1068Microsoft SQL Server Remote Code Execution Vulnerability
    7.0 · Actively exploited
  • CVE-2026-69836Microsoft Entra
    5.3 · Actively exploited

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities