CVE-2021-0226

Name: CVE-2021-0226
Creator: NVD / NIST
Published: 2021-04-22T20:15:08.497+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.88%

Last modified Jun 17, 2026

CVE-2021-0226 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.88% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.88%

54.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos Os Evolved	20.1	R1
Juniper	Junos Os Evolved	20.2	R1
Juniper	Junos Os Evolved	20.3	R1

References

https://kb.juniper.net/JSA11121Vendor Advisory
https://kb.juniper.net/JSA11121Vendor Advisory

Timeline

Published: Apr 22, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-0226?

How severe is CVE-2021-0226?

CVE-2021-0226 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.88% probability of exploitation in the next 30 days.

How do I fix CVE-2021-0226?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-0226?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST