How severe is CVE-2020-0646?

CVE-2020-0646 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-0646 being actively exploited?

Yes. CVE-2020-0646 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-2020-0646?

CVE-2020-0646 primarily affects Microsoft .net Framework. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-0646?

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-2020-0646 have an EU (EUVD) identifier?

Yes. CVE-2020-0646 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-2140. It is also flagged as exploited in the EUVD (since 2021-11-03).

When was CVE-2020-0646 published?

CVE-2020-0646 was published on 2020-01-14 and last updated on 2026-06-17.

CVE-2020-0646

CVE-2020-0646 is a critical-severity vulnerability in Microsoft .net Framework with a CVSS 3.x base score of 9.8. 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-91.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 99% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-11-03)
EU (EUVD) id: EUVD-2020-2140
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-11-03)
Weakness: CWE-91
Affected product: Microsoft .net Framework
Published: 2020-01-14
Last modified: 2026-06-17

Description

A remote code execution vulnerability exists when the Microsoft .NET Framework fails to validate input properly, aka '.NET Framework Remote Code Execution Injection Vulnerability'.

Frequently asked questions

What is CVE-2020-0646?: A remote code execution vulnerability exists when the Microsoft .NET Framework fails to validate input properly, aka '.NET Framework Remote Code Execution Injection Vulnerability'.
How severe is CVE-2020-0646?: CVE-2020-0646 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-0646 being actively exploited?: Yes. CVE-2020-0646 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-2020-0646?: CVE-2020-0646 primarily affects Microsoft .net Framework. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-0646?: 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-2020-0646 have an EU (EUVD) identifier?: Yes. CVE-2020-0646 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-2140. It is also flagged as exploited in the EUVD (since 2021-11-03).
When was CVE-2020-0646 published?: CVE-2020-0646 was published on 2020-01-14 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:a:microsoft:.net_framework:3.0:sp2:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:3.5:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.6.2:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7.1:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.7.2:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.8:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:3.5.1:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.5.2:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.6:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:.net_framework:4.6.1:*:*:*:*:*:*:*

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