CVE-2026-57020

Name of the Vulnerable Software and Affected Versions Junos OS on QFX10000 Series versions prior to 23.2R2-S7 Junos OS on QFX10000 Series versions 23.4 through 23.4R2-S8 Junos OS on QFX10000 Series versions 24.2 through 24.2R2-S4 Junos OS on QFX10000 Series versions 24.4 through 24.4R2-S4

Description An improper check for unusual or exceptional conditions in the packet forwarding engine (pfe) allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). In an EVPN-VxLAN scenario, sending IPv6 multicast traffic to the non-IRB interface of a spine switch triggers a flood of packets to other spines and all Ethernet Segment Identifier (ESI) leaf switches. This results in an endless forwarding loop that can saturate involved links and disrupt legitimate traffic.

Recommendations Update to version 23.2R2-S7 or later. Update to version 23.4R2-S8 or later. Update to version 24.2R2-S4 or later. Update to version 24.4R2-S4 or later.