How severe is CVE-2021-31979?

CVE-2021-31979 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-31979 being actively exploited?

Yes. CVE-2021-31979 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-31979?

CVE-2021-31979 primarily affects Microsoft Windows 10 1507. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-31979?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-31979 have an EU (EUVD) identifier?

Yes. CVE-2021-31979 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-18851. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2021-31979 published?

CVE-2021-31979 was published on 2021-07-14 and last updated on 2026-06-17.

CVE-2021-31979

CVE-2021-31979 is a high-severity vulnerability in Microsoft Windows 10 1507 with a CVSS 3.x base score of 7.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-11-03). The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2021-18851
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Weakness: CWE-119
Affected product: Microsoft Windows 10 1507
Published: 2021-07-14
Last modified: 2026-06-17

Description

Windows Kernel Elevation of Privilege Vulnerability

Frequently asked questions

What is CVE-2021-31979?: Windows Kernel Elevation of Privilege Vulnerability
How severe is CVE-2021-31979?: CVE-2021-31979 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-31979 being actively exploited?: Yes. CVE-2021-31979 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-11-03, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-31979?: CVE-2021-31979 primarily affects Microsoft Windows 10 1507. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-31979?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-31979 have an EU (EUVD) identifier?: Yes. CVE-2021-31979 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-18851. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2021-31979 published?: CVE-2021-31979 was published on 2021-07-14 and last updated on 2026-06-17.

References

Affected products (18)

cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Windows 10 1507

CVE-2025-53766 — Critical (CVSS 9.8): Heap-based buffer overflow in Windows GDI+ allows an unauthorized attacker to execute code over a network.
CVE-2025-47981 — Critical (CVSS 9.8): Heap-based buffer overflow in Windows SPNEGO Extended Negotiation allows an unauthorized attacker to execute code over…
CVE-2025-21307 — Critical (CVSS 9.8): Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability
CVE-2025-21298 — Critical (CVSS 9.8): Windows OLE Remote Code Execution Vulnerability
CVE-2024-49112 — Critical (CVSS 9.8): Windows Lightweight Directory Access Protocol (LDAP) Remote Code Execution Vulnerability
CVE-2024-43491 — Critical (CVSS 9.8): Microsoft is aware of a vulnerability in Servicing Stack that has rolled back the fixes for some vulnerabilities…

All CVEs affecting Microsoft Windows 10 1507 →

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →