Is CVE-2019-0820 being actively exploited?

CVE-2019-0820 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2019-0820?

CVE-2019-0820 has a CVSS 3.1 base score of 7.5 (HIGH).

CVE-2019-0820

HIGH · CVSS 7.5EPSS 5.7%EU EUVD

A denial of service vulnerability exists when .NET Framework and .NET Core improperly process RegEx strings, aka '.NET Framework and .NET Core Denial of Service Vulnerability'. This CVE ID is unique from CVE-2019-0980, CVE-2019-0981.

Key facts

CVSS score: 7.5 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400
EPSS score: 5.7% (93th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2021-1682)
Published: May 16, 2019
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-1682 in the EU Vulnerability Database. Last updated in EUVD on August 4, 2024.

View on the EU Vulnerability Database

Affected products

microsoft / .net core
microsoft / .net core
microsoft / .net core
microsoft / .net core
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / .net framework
microsoft / windows 10
microsoft / windows 10
microsoft / windows 10
microsoft / windows 10
microsoft / windows 10
microsoft / windows 10
microsoft / windows 10
microsoft / windows 7
microsoft / windows 8.1
microsoft / windows rt 8.1
microsoft / windows server 2008
microsoft / windows server 2008
microsoft / windows server 2008
microsoft / windows server 2012
microsoft / windows server 2012
microsoft / windows server 2016
microsoft / windows server 2016
microsoft / windows server 2016
microsoft / windows server 2019
redhat / enterprise linux
redhat / enterprise linux eus
redhat / enterprise linux eus
redhat / enterprise linux eus
redhat / enterprise linux eus
redhat / enterprise linux server aus
redhat / enterprise linux server aus
redhat / enterprise linux server aus
redhat / enterprise linux server tus
redhat / enterprise linux server tus
redhat / enterprise linux server tus

Certified products that may be affected

26 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Red Hat Enterprise Linux 8 NSS Cryptographic Module - Red Hat, Inc. - FIPS 140 5513 - active
Red Hat Enterprise Linux 8 Kernel Cryptographic API - Red Hat, LLC - FIPS 140 5461 - active
Red Hat Enterprise Linux 8 Kernel Cryptographic API - Red Hat, Inc. - FIPS 140 5089 - active
Red Hat Enterprise Linux 8.6 - Red Hat, Inc. - Common Criteria CCEVS-VR-VID-11309-2024 - archived
Red Hat Enterprise Linux 8 OpenSSL Cryptographic Module - Red Hat®, Inc. - FIPS 140 4642 - historical

See all 26 in the Security Certifications Explorer.

References

https://access.redhat.com/errata/RHSA-2019:1259(Third Party Advisory)
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0820(Patch, Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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