Juniper Junos OS Evolved (QFX5000 / PTX, multicast packet handling): FABRIC DOS: crafted multicast packets crash

CVE-2025-59969Firmware, BMC & network fabriccurated

Impact

FABRIC DOS: crafted multicast packets crash and restart evo-aftmand / evo-pfemand — the forwarding-plane management daemons on Junos Evolved. Affects QFX5000-series and PTX, both of which appear in AI-cluster spine and super-spine roles. Multicast is reachable from any tenant that can source it, and the crash takes the forwarding plane with it.

Who can reach it

An attacker able to send crafted multicast packets into the fabric — any tenant workload on a VLAN the device serves.

What to do

Junos Evolved upgrade plus reboot. Interim: rate-limit or filter unexpected multicast at the fabric edge with a control-plane policer — live config. If your cluster does not use multicast (most GPU fabrics do not, outside of some MPI transports), block it outright at the edge.

References

https://supportportal.juniper.net/s/article/2026-04-Security-Bulletin-Junos-OS-Evolved-QFX5000-Series-and-PTX-Series-An-attacker-sending-crafted-multicast-packets-will-cause-evo-aftmand-evo-pfemand-to-crash-and-restart-CVE-2025-59969

This entry is curated: imported from vendor advisories with machine assistance, not yet individually verified. Confirm against your vendor's advisory before acting, and report anything wrong.