CVE-2021-26411

mediumpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.817 · 100 %ileexploit · PoCEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV · 1 exploit · PoC

Likely / severe?

81.7% (100th) EPSS

CVSS 5.1 · medium

Is it mine?

14 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · msrc_csaf

added 2021-11-03remediate by 2021-11-17

required action Apply updates per vendor instructions.

EPSS · scored 2026-10-26

Microsoft Internet Explorer Memory Corruption Vulnerability

Internet Explorer Memory Corruption Vulnerability

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedInternet Explorer 11msrc_csaf
IE Cumulative:https://support.microsoft.com/help/5000800
https://support.microsoft.com/help/5000800
FixedInternet Explorer 9msrc_csaf
IE Cumulative:https://support.microsoft.com/help/5000800
https://support.microsoft.com/help/5000800
FixedMicrosoft Edge (EdgeHTML-based)msrc_csaf
10.0.19043.867:Security Update:https://support.microsoft.com/help/5000802
https://support.microsoft.com/help/5000802

cvss

Technical severity, 0–10. One row per scoring source.

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.1–8.8

v2.05.1mediumAV:N/AC:H/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 4.9 · impact 6.4

v2.05.1mediumAV:N/AC:H/Au:N/C:P/I:P/A:P/E:Hsecondary · CVSS-BT (t0sche)

v3.18highAV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:Lsecondary · secure@microsoft.com USexploitability 2.8 · impact 5.3

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:Csecondary · Microsoft Security Response Center US

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L/E:P/RL:O/RC:Csecondary · ENISA EU

v3.18.8highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:Hsecondary · NVD / NIST USexploitability 2.8 · impact 5.9

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-416USprimaryCWE-415US

exploits (1)

Public proof-of-concept and weaponised exploit code.

CrackerCat/CVE-2021-26411CrackerCat/CVE-2021-26411PoC · poc_in_github

affected products (14)

Products and version ranges known to be affected.

Microsoft Internet Explorer 111.0.0 → publicationenisa_euvdEU
Microsoft Internet Explorer 91.0.0 → publicationenisa_euvdEU
Microsoft Microsoft Edge (EdgeHTML-based)1.0..0 → publicationenisa_euvdEU
Microsoft Corp Internet Explorer≤ 11fstec_bduRU
Microsoft Corp Microsoft Edgeall versionsfstec_bduRU
Internet Explorer 11all versionsfixedmsrc_csafUS
Internet Explorer 11< 6.3.9600.19968msrc_csafUS
Internet Explorer 9all versionsfixedmsrc_csafUS
Internet Explorer 9< 6.0.6003.21070msrc_csafUS
Microsoft Edge (EdgeHTML-based)all versionsfixedmsrc_csafUS
Microsoft Edge (EdgeHTML-based)< 10.0.19043.867msrc_csafUS
microsoft edgeall versionsnvdUScpe:2.3:a:microsoft:edge:*:*:*:*:*:*:*:*
microsoft internet explorer= 11nvdUScpe:2.3:a:microsoft:internet_explorer:*:*:*:*:*:*:*:*
microsoft internet explorer= 9nvdUScpe:2.3:a:microsoft:internet_explorer:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

msrc_CVE-2021-26411Internet Explorer Memory Corruption Vulnerability2021-03-09csaf · msrc_csafUS
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu msrc_csaf nvd NVD CVE.org MITRE

published 2021-03-11modified 2026-08-19

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+12130 more

references (8)

External citations — patches, advisories, analysis.

scry

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