CVE-2020-0878
HighExploitedPublic exploitA remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory.
Published Sep 11, 2020 · Updated Feb 23, 2026
Key Facts
Patch immediately- CVE-2020-0878 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Chakracore (Microsoft), Edge (Microsoft), Internet Explorer (Microsoft).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 2.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including Chakracore publication, Edge publication, Internet Explorer publication.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
2.7%
Higher than 85.6% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2020-0878 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
A remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory. The vulnerability could corrupt memory in a way that could allow an attacker to 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, the attacker 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.
An attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft browsers, and then convince a user to view the website. The attacker could also take advantage of compromised websites, or websites that accept or host user-provided content or advertisements, by adding specially crafted content that could exploit the vulnerability. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically via an enticement in email or instant message, or by getting them to open an email attachment.
The security update addresses the vulnerability by modifying how Microsoft browsers handle objects in memory.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Nov 3, 2021 | May 3, 2022 | Known |
| Industry KEV feed | Nov 3, 2021 | May 3, 2022 | Known |
| CIRCL KEV | Nov 3, 2021 | May 3, 2022 | Known |
| ENISA EUVD | Nov 3, 2021 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
5 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ChakracoreMicrosoft | See advisory | publication |
| EdgeMicrosoft | See advisory | publication |
| Internet ExplorerMicrosoft | 11, 9 | publication |
Patched Releases
Chakracore
publication
Edge
publication
Internet Explorer
publication
Timeline
Publicly disclosed
Sep 11, 2020
Added to CISA KEV
Nov 3, 2021
Added to Industry KEV feed
Nov 3, 2021
Added to CIRCL KEV
Nov 3, 2021
Added to ENISA EUVD
Nov 3, 2021
Last updated
Feb 23, 2026
Weakness Type
- CWE-787 Out-of-bounds Write
References
FAQ
Common Questions.
A remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory.
Affected: Chakracore (Microsoft); Edge (Microsoft); Internet Explorer (Microsoft) versions 11, 9. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Nov 3, 2021 and is known to be used in ransomware campaigns.
Yes. It was added on Nov 3, 2021 with a federal remediation due date of May 3, 2022.
Public exploit code is available.
Fixed versions are available, including Chakracore publication, Edge publication, Internet Explorer publication.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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