CVE Intelligence
CISA KEV High

CVE-2022-21971 — Microsoft Windows Runtime Remote Code Execution Vulnerability

Windows Runtime Remote Code Execution Vulnerability

Published Feb 9, 2022 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, GitHub Security Advisories, CVE Program (cve.org) e CISA ADP · CNA: microsoft

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (github)+6
  • EPSS 53.9% (30-day exploitation probability)+15
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Aug 18, 2022
EPSS FIRST
53.93%
ahead of 99% of scored CVEs · Oct 14, 2026
Affects
Microsoft
Windows 10 1809 and 16 more
CVSS base
7.8
High · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Sep 8, 2022 — passed 1498 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Microsoft Windows 10 1809, Microsoft Windows 10 1909, Microsoft Windows 10 20h2…).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. Apply the fixed version or the patch documented under Remediation.
  4. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  5. EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
  6. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Microsoft Windows 10 1809 < 10.0.17763.2565 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 1909 < 10.0.18363.2094 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 20h2 < 10.0.19042.1526 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 21h1 < 10.0.19043.1526 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 21h2 < 10.0.19044.1526 Vulnerable NIST National Vulnerability Database
Microsoft Windows 10 Version 1809 ≥ 10.0.0 and < 10.0.17763.2565≥ 10.0.17763.0 and < 10.0.17763.2565 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 1909 ≥ 10.0.0 and < 10.0.18363.2094 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 20H2 ≥ 10.0.0 and < 10.0.19042.1526 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 21H1 ≥ 10.0.0 and < 10.0.19043.1526 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 10 Version 21H2 ≥ 10.0.19043.0 and < 10.0.19044.1526 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows 11 21h2 < 10.0.22000.493 Vulnerable NIST National Vulnerability Database
Microsoft Windows 11 version 21H2 ≥ 10.0.0 and < 10.0.22000.493 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2019 ≥ 10.0.17763.0 and < 10.0.17763.2565 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2019 < 10.0.17763.2565 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 2019 (Server Core installation) ≥ 10.0.17763.0 and < 10.0.17763.2565 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2022 ≥ 10.0.20348.0 and < 10.0.20348.524 Vulnerable CVE Program (cve.org) e CISA ADP
Microsoft Windows Server 2022 < 10.0.20348.524 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server 20h2 < 10.0.19042.1526 Vulnerable NIST National Vulnerability Database
Microsoft Windows Server version 20H2 ≥ 10.0.0 and < 10.0.19042.1526 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 secure@microsoft.com via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.8 CVSS 3.1 High — — microsoft via CVE Program (cve.org) e CISA ADP
9.3 CVSS 2.0 High 8.6 10.0 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H (score shown at the top: secure@microsoft.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-824

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Aug 18, 2022
Federal deadline
Sep 8, 2022
passed 1498 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 53.93%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Hunt retroactively in logs from before Aug 18, 2022 (KEV listing): exploitation may have started earlier.
endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · microsoft/windows 10 version 1809, microsoft/windows server 2019, microsoft/windows server 2019 (server core installatio
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • Affected products added · microsoft/windows 10 1809, microsoft/windows 10 1909, microsoft/windows 10 20h2, microsoft/windows 10 21h1, microsoft/wi
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 7.8
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • 2022
  • Added to CISA KEV catalog
    Aug 17, 2022 · CISA
  • CVE published
    Feb 9, 2022 · microsoft

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

5 on the record

Elsewhere on this site

Microsoft
every CVE for this vendor
2022-08
what else CISA listed that month
CWE-824
other pages naming this weakness

Related CVEs (same products)

  • Medium CVE-2026-97844 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97841 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97840 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97839 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97843 Role: DNS Server Information Disclosure Vulnerability 2d
  • Medium CVE-2026-97842 Role: DNS Server Information Disclosure Vulnerability 2d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2022-21971 is "Microsoft Windows Runtime Remote Code Execution Vulnerability", rated High. It affects Windows 10 1809 (Microsoft); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 53.93% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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