CVE-2020-1651: Juniper Junos

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

On Juniper Networks MX series, receipt of a stream of specific Layer 2 frames may cause a memory leak resulting in the packet forwarding engine (PFE) on the line card to crash and restart, causing traffic interruption. By continuously sending this stream of specific layer 2 frame, an attacker connected to the same broadcast domain can repeatedly crash the PFE, causing a prolonged Denial of Service (DoS). This issue affects Juniper Networks Junos OS on MX Series: 17.2 versions prior to 17.2R3-S4; 17.2X75 versions prior to 17.2X75-D105.19; 17.3 versions prior to 17.3R3-S7; 17.4 versions prior to 17.4R1-S3, 17.4R2; 18.1 versions prior to 18.1R2. This issue does not affect Juniper Networks Junos OS releases prior to 17.2R1.

Affected products

• Juniper Junos: version 17.2 only; version 17.2x75 only; version 17.3 only; version 17.4 only; version 18.1 only

Published 2020-07-17. Last modified 2026-06-17.