CVE-2021-0226 Junos OS Evolved: The IPv6 BGP session will flap due to receipt of a specific IPv6 packet
Attackers can cause IPv6 BGP session termination and sustained denial of service on Juniper Junos OS Evolved devices by sending specific IPv6 packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-0226?
CVE-2021-0226 is a high-severity denial of service vulnerability in Juniper Junos Os Evolved, published on 22 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-665
Which versions are affected by CVE-2021-0226?
It affects 1 product.
Products include Juniper Junos Os Evolved.
How do I fix CVE-2021-0226?
No fix has been published for CVE-2021-0226 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-0226 being exploited?
There is no known exploitation of CVE-2021-0226 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos Os Evolved
- CVE-2026-21902 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
- CVE-2023-28983 Junos OS Evolved: Shell Injection vulnerability in the gNOI server
- CVE-2025-21599 Denial of service in Junos OS Evolved
- CVE-2024-47502 Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS
- CVE-2024-39531 Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols
Sources
Also known as GHSA-7jmp-9phw-35g8.