CVE-2018-8653
CVE-2018-8653 is a security flaw in Microsoft Internet Explorer, Microsoft’s old web browser, still built into Windows. Attackers can run their own code on Microsoft Internet Explorer. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Nov 2021.[1]
Microsoft Internet Explorer is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Microsoft has published a fix or advice.
Description
CISA calls it a scripting engine memory corruption in Microsoft Internet Explorer. In its words: “Microsoft Internet Explorer contains a memory corruption vulnerability due to how the Scripting Engine handles objects in memory, leading to remote code execution.”[1]
The CVE record adds: “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.”[2]
The underlying weakness is out-of-bounds write (CWE-787), in MITRE’s list of common software weaknesses.
It scores 7.5 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Microsoft’s advisory has them[3]. CISA names the product as Microsoft Internet Explorer.
Every device with Microsoft Internet Explorer needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 1,049 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 May 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 30%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Microsoft has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Update Microsoft Internet Explorer now.Install the latest update from Microsoft on every device that has it, and restart when asked. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 30%.[4] |
See also
Other Microsoft Internet Explorer flaws
- CVE-2010-0806: use-after-free ·
- CVE-2010-0249: use-after-free ·
- CVE-2010-3962: uninitialized memory corruption ·
- CVE-2013-3893: resource management errors ·
- CVE-2012-4792: use-after-free ·
- CVE-2013-3163: memory corruption ·
Other Microsoft flaws
- CVE-2026-96951, Microsoft Windows: command injection ·
- CVE-2026-65660, Microsoft SharePoint: code injection ·
- CVE-2026-85880, Microsoft Windows: heap-based buffer overflow ·
- CVE-2026-81963, Microsoft Windows: link following ·
- CVE-2019-1068, Microsoft SQL Server: remote code execution ·
Other out-of-bounds write flaws
- CVE-2026-86950, Apple devices: out-of-bounds write ·
- CVE-2026-53266, Linux Kernel: out-of-bounds write ·
- CVE-2026-87491, Chrome and other Chromium browsers: out of bounds write ·
- CVE-2026-53362, Linux Kernel: unspecified ·
- CVE-2022-0995, Linux Kernel: out-of-bounds write ·
Added the same day
- CVE-2021-42258, BQE BillQuick Web Suite: SQL injection ·
- CVE-2021-42013, Apache HTTP Server: path traversal ·
- CVE-2021-41773, Apache HTTP Server: path traversal ·
- CVE-2021-40539, Zoho ManageEngine: aDSelfService plus authentication bypass ·
- CVE-2021-40444, Microsoft MSHTML: remote code execution ·
Every Microsoft flaw on CISA’s list · Everything added in November 2021
References
- ^ Cybersecurity and Infrastructure Security Agency. “Microsoft Internet Explorer Scripting Engine Memory Corruption Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
- ^ National Institute of Standards and Technology. “CVE-2018-8653 Detail”. National Vulnerability Database, published 20 Dec 2018.
- ^ Microsoft. Advisories and fixes: portal.msrc.microsoft.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.296, percentile 98.2, 31 Oct 2026.
- CVE Program. “CVE-2018-8653”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.