CVE Intelligence
CISA KEV High Memory corruption

CVE-2018-8653 — 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, aka "Scripting Engine Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10. This CVE ID is unique from CVE-2018-8643.

Published Dec 20, 2018 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: microsoft

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • EPSS 29.6% (30-day exploitation probability)+15
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Nov 3, 2021
EPSS FIRST
29.61%
ahead of 98% of scored CVEs · Oct 14, 2026
Affects
Microsoft
Internet Explorer and 3 more
CVSS base
7.5
High · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: May 3, 2022 — passed 1626 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Microsoft Internet Explorer, Microsoft Internet Explorer 10, Microsoft Internet Explorer 11…).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. Apply the fixed version or the patch documented under Remediation.
  5. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  6. EPSS ahead of 98% of scored CVEs: prioritize it in the patch queue.
  7. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Microsoft Internet Explorer version 10version 11version 9 Vulnerable NIST National Vulnerability Database
Microsoft Internet Explorer 10 version Windows Server 2012 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Internet Explorer 11 version Windows 10 Version 1809 for 32-bit Systemsversion Windows Server 2019version Windows Server 2016version Windows Server 2012 R2version Windows Server 2008 R2 for x64-based Systems Service Pack 1version Windows RT 8.1version Windows 8.1 for x64-based systemsversion Windows 8.1 for 32-bit systems
and 16 more version Windows 7 for x64-based Systems Service Pack 1version Windows 7 for 32-bit Systems Service Pack 1version Windows 10 Version 1809 for x64-based Systemsversion Windows 10 Version 1809 for ARM64-based Systemsversion Windows 10 Version 1803 for x64-based Systemsversion Windows 10 Version 1803 for ARM64-based Systemsversion Windows 10 Version 1803 for 32-bit Systemsversion Windows 10 Version 1709 for x64-based Systemsversion Windows 10 Version 1709 for ARM64-based Systemsversion Windows 10 Version 1709 for 32-bit Systemsversion Windows 10 Version 1703 for x64-based Systemsversion Windows 10 Version 1703 for 32-bit Systemsversion Windows 10 Version 1607 for x64-based Systemsversion Windows 10 Version 1607 for 32-bit Systemsversion Windows 10 for x64-based Systemsversion Windows 10 for 32-bit Systems
Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Internet Explorer 9 version Windows Server 2008 for 32-bit Systems Service Pack 2version Windows Server 2008 for x64-based Systems Service Pack 2 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.5 CVSS 3.1 High 1.6 5.9 nvd@nist.gov via NIST National Vulnerability Database
7.5 CVSS 3.1 High 1.6 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
7.5 CVSS 3.1 High — — CISA-ADP via CVE Program (cve.org) e CISA ADP
7.5 CVSS 3.0 High — — GitHub, Inc. via GitHub Security Advisories
7.6 CVSS 2.0 High 4.9 10.0 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-787 · Out-of-bounds Write

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Nov 3, 2021
Federal deadline
May 3, 2022
passed 1626 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 29.61%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
  • Hunt retroactively in logs from before Nov 3, 2021 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • Affected products added · microsoft/internet explorer
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 13, 2026
  • Affected products added · microsoft/internet explorer 9, microsoft/internet explorer 11, microsoft/internet explorer 10
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • CVSS changed · 7.5
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2021
  • Added to CISA KEV catalog
    Nov 2, 2021 · CISA
  • 2018
  • CVE published
    Dec 20, 2018 · microsoft

Source activity

Repeated readings are counted rather than listed.

  • 3× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

5 on the record

Elsewhere on this site

Microsoft
every CVE for this vendor
2021-11
what else CISA listed that month
CWE-787
other pages naming this weakness

Related CVEs (same products)

  • High CVE-2021-27085 Microsoft Internet Explorer Remote Code Execution Vulnerability KEV Mar 11, 2021
  • High CVE-2021-26411 Microsoft Internet Explorer Memory Corruption Vulnerability KEV Mar 11, 2021
  • Medium CVE-2020-0878 Microsoft Edge and Internet Explorer Memory Corruption Vulnerability KEV Sep 11, 2020
  • High CVE-2020-1380 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Aug 17, 2020
  • High CVE-2020-0968 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Apr 15, 2020
  • High CVE-2020-0674 Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability KEV Feb 11, 2020

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2018-8653 is "Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability", rated High. It affects Internet Explorer (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.5 describes technical severity. EPSS 29.61% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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