CVE-2021-0226: Juniper Junos OS Evolved

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

On Juniper Networks Junos OS Evolved devices, receipt of a specific IPv6 packet may cause an established IPv6 BGP session to terminate, creating a Denial of Service (DoS) condition. Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue does not affect IPv4 BGP sessions. This issue affects IBGP or EBGP peer sessions with IPv6. This issue affects: Juniper Networks Junos OS Evolved: 19.4 versions prior to 19.4R2-S3-EVO; 20.1 versions prior to 20.1R2-S3-EVO; 20.2 versions prior to 20.2R2-S1-EVO; 20.3 versions prior to 20.3R2-EVO. This issue does not affect Juniper Networks Junos OS releases.

Affected products

• Juniper Junos OS Evolved: version 20.1 only; version 20.2 only; version 20.3 only

Published 2021-04-22. Last modified 2026-06-17.