CVE-2026-57031

Name of the Vulnerable Software and Affected Versions Junos OS on MX Series versions 23.2R2-S1 through 23.2R2-S6 Junos OS on MX Series versions 23.4R2 through 23.4R2-S6 Junos OS on MX Series versions prior to 24.2R2-S3 Junos OS on MX Series versions prior to 24.4R2-S2 Junos OS on MX Series versions prior to 25.2R2

Description An improper check for unusual or exceptional conditions in the packet forwarding engine (PFE) allows adjacent subscribers to bypass configured firewall filters. On MX Series devices with MPC10/11, LC4800/9600, and MX304 using subscribers configured on static interfaces, ingress firewall filters are not enforced. This results in a failure to apply protocol level and upstream bandwidth limitations.

Recommendations Update Junos OS on MX Series to version 23.2R2-S7 or later. Update Junos OS on MX Series to version 23.4R2-S7 or later. Update Junos OS on MX Series to version 24.2R2-S3 or later. Update Junos OS on MX Series to version 24.4R2-S2 or later. Update Junos OS on MX Series to version 25.2R2 or later.