CVE-2026-57027

Name of the Vulnerable Software and Affected Versions Junos OS EX4100 Series versions prior to 23.2R2-S7 Junos OS EX4400 Series versions prior to 23.2R2-S7 Junos OS EX4100 Series versions 23.4 through 23.4R2-S7 Junos OS EX4400 Series versions 23.4 through 23.4R2-S7 Junos OS EX4100 Series versions 24.2 through 24.2R2-S4 Junos OS EX4400 Series versions 24.2 through 24.2R2-S4 Junos OS EX4100 Series versions 24.4 through 24.4R2 Junos OS EX4400 Series versions 24.4 through 24.4R2

Description A memory leak exists in the packet forwarding engine (pfe) of specific EX Series devices. This occurs when sFlow is configured in a Virtual Chassis (VC) scenario and multicast traffic is received on one VC member and transmitted through another. An unauthenticated adjacent attacker can exploit this to cause a Denial-of-Service (DoS), leading to a Flexible PIC Concentrator (FPC) crash and subsequent restart.

Recommendations Update EX4100 and EX4400 Series to version 23.2R2-S7 or later. Update EX4100 and EX4400 Series to version 23.4R2-S7 or later. Update EX4100 and EX4400 Series to version 24.2R2-S4 or later. Update EX4100 and EX4400 Series to version 24.4R2 or later.