Known exploited · Microsoft
CVE-2020-0878: Microsoft Edge and Internet Explorer Memory Corruption Vulnerability
What it is
Microsoft Edge and Internet Explorer contain a memory corruption vulnerability that allows attackers to execute code in the context of the current user.
- Vendor
- Microsoft
- Product
- Edge and Internet Explorer
- Added to KEV
- November 3, 2021
- CISA due date
- May 3, 2022
- Ransomware use
- Known
- Weakness
- CWE-787: Out-of-bounds Write
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of Edge and Internet Explorer you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before May 3, 2022 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.