CVE record · CVE-2021-27085

Internet Explorer Remote Code Execution Vulnerability

CVSS 8.8 HighCriticalIn CISA KEVEPSS 0.054 · 92nd percentile

Critical, because:

In CISA’s KEV catalogue since 3 Nov 2021: it is known to be exploited.

Published by the CVE Program (CNA: microsoft) at 11 Mar 2021, 15:46 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Microsoft	Internet Explorer 11	affected 1.0.0 to before 10.0.17134.2087 custom

Identifiers: CVE-2021-27085
CNA: microsoft
Tags: Microsoft Internet Explorer 11
Published: 11 Mar 2021
Updated: 19 Aug 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.8	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:C	CNA (microsoft)

CISA KEV Listed since 3 Nov 2021: known to be exploited.
EPSS 0.054, the 92nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 11 Mar 2021. New records show when each source confirmed them.

Sources

References from the CNA

msrc.microsoft.com/update-guide/vulnerability/CVE-2021-27085 vendor-advisorypatch

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.